Introduction

Forty years is a long time—I would know, as it almost perfectly encapsulates my entire lifetime (I was born less than a month after the Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc.¹467 U.S. 837 (1984). decision and am therefore in a very real sense a “Chevron Baby”). Unsurprisingly, the nearly forty-year life of the Chevron doctrine saw phases of growth, maturity, evolution, and decline.²I cannot claim credit for first seeing parallels between Chevron and the rollercoaster of life. See Linda Jellum, Chevron’s Demise: A Survey of Chevron from Infancy to Senescence, 59 Admin. L. Rev. 725, 730 (2007); Michael Herz, Chevron is Dead; Long Live Chevron, 115 Colum. L. Rev. 1867, 1909 (2015). Now, in Loper Bright Enterprises v. Raimondo³45 F.4th 359 (D.C. Cir. 2022), cert. granted in part, 143 S. Ct. 2429 (argued Jan. 17, 2024) (mem.). and Relentless, Inc. v. Department of Commerce,⁴62 F.4th 621 (1st Cir. 2023), cert. granted in part, 144 S. Ct. 325 (argued Jan. 17, 2024) (mem.). the doctrine appears ready to face life’s ultimate milestone. One can already faintly hear the doctrine’s opponents dancing on Chevron’s tombstone, as well as the soft, resigned murmurs of mourning from its supporters. All seem to accept that Chevron’s time has come.

Except legal ideas and doctrines, unlike people, never actually die.

This Article, through a simple positive political theory model, defends the proposition that although at death’s door (to keep the metaphor going), Chevron deference is likely to be resurrected.⁵See infra Part II. The core insight of this model is that the prevailing approach to judicial review of agency interpretations of law is politically contingent. That is, such review likely represents an equilibrium that efficiently maximizes the U.S. Supreme Court’s policymaking utility over the long haul, given certain institutional constraints on the Supreme Court Justices. The model produces four possible futures of Chevron deference, with each possible future’s probability depending on the Court’s certainty about the future allyship or opposition of the executive branch.⁶The Article’s title, and, indeed, its spirit of modeling doctrinal change, is inspired by Professor Andrew Coan. See Andrew Coan, Eight Futures of the Nondelegation Doctrine, 2020 Wis. L. Rev. 141, 147–51 (2020) (sketching six possible future scenarios for nondelegation depending on judicial capacity).

If one entertains this starting point, it turns out that something like Chevron deference follows when judges are highly confident that a particular configuration of regime politics is occurring, and will occur, over some time. As explained below, this particular configuration existed at Chevron’s founding moment but has eroded in recent decades, making it highly likely that Chevron will be abandoned, or at least significantly curtailed, by the Supreme Court.⁷See infra Part I. Yet, as this Article also shows, the particular configuration conducive to Chevron deference will likely reemerge at some point in the future. At that point, it will be only a matter of time until the Supreme Court gains the confidence to bring deference back to life.⁸See infra Part III. Indeed, the political conditions currently eroding the utility of Chevron for the Supreme Court are historically anomalous, and anomalies usually dissipate with time.⁹See infra Section III.A. While forty years is practically a whole lifetime for people, it is hardly a blip in political time.

The Article unfolds as follows. Part I provides a brief political history of Chevron deference. Recent work in this vein has helped us to better appreciate the political contingency of the rise and decline of Chevron deference.¹⁰See, e.g., Craig Green, Deconstructing the Administrative State: Chevron Debates and the Transformation of Constitutional Politics, 101 B.U. L. Rev. 619, 657–68 (2021); Gregory A. Elinson & Jonathan S. Gould, The Politics of Deference, 75 Vand. L. Rev. 475, 478 (2022); Thomas W. Merrill, The Chevron Doctrine: Its Rise and Fall, and the Future of the Administrative State 6 (2022). Part II builds on this insight, articulating a simple model that can tell us under what political conditions something like Chevron deference is likely to arise, as well as when it is likely to fade or disappear completely. Unlike other accounts that proclaim Chevron’s “inevitability,”¹¹Nicholas R. Bednar & Kristin E. Hickman, Chevron’s Inevitability, 85 Geo. Wash. L. Rev. 1392, 1398–99 (2017); see Adrian Vermeule, Law’s Abnegation: From Law’s Empire to the Administrative State 13–14 (2016). the model this Article offers differs in its parsimonious focus on political circumstance and preference maximization, as well as in its forthright acknowledgment that Chevron may very well not be inevitable in any given moment if the right political circumstances for its erosion exist. Part III then engages with political science literature to argue that, while political conditions do not favor Chevron deference currently, in the long run they are almost certain to. Indeed, this Article will argue that regime theory teaches us that the conditions favoring Chevron deference serve as a natural default for our political system.¹²See infra Part III. Thus, if the model bears any relationship to the reality of what really drives the Court’s construction of deference doctrines, we likely have not seen the last of Chevron deference.

I.      Chevron Politics

It is, of course, possible to approach Chevron deference through a purely doctrinal lens. Viewed this way, Chevron deference is simply the rule, dating back to 1984, that courts must defer to the reasonable interpretations of statutes offered by agencies if the statute itself does not precisely answer the question presented.¹³Chevron U.S.A. Inc. v. Nat. Res. Def. Council, Inc., 467 U.S. 837, 842–43, 845 (1984). In other words, Chevron deference says that agencies, not courts, get to decide how to exercise the discretion inherent in the interpretation of ambiguous statutory language.¹⁴Matthew C. Stephenson & Adrian Vermeule, Chevron Has Only One Step, 95 Va. L. Rev. 597, 601 (2009). Forests have been laid to waste unpacking the nuances of the doctrine,¹⁵See, e.g., id. at 597–98; Cary Coglianese, Foreword, Chevron’s Interstitial Steps, 85 Geo. Wash. L. Rev. 1339, 1345–46 (2017); Daniel J. Hemel & Aaron L. Nielson, Chevron Step One-and-a-Half, 84 U. Chi. L. Rev. 757, 765 (2017); Thomas W. Merrill & Kristin E. Hickman, Chevron’s Domain, 89 Geo. L.J. 833, 835–37 (2001); Lisa Schultz Bressman, How Mead Has Muddled Judicial Review of Agency Action, 58 Vand. L. Rev. 1443, 1450–51 (2005); Note, Major Question Objections, 129 Harv. L. Rev. 2191, 2192 (2016). which have grown exponentially as courts have struggled with the boundaries of deference. And, of course, like any doctrine with stakes this high, Chevron has inspired a deep normative and legal debate about its provenance and propriety.¹⁶See generally Christopher J. Walker, Attacking Auer and Chevron Deference: A Literature Review, 16 Geo. J.L. & Pub. Pol’y 103 (2018) (providing a literature review of arguments “to eliminate or narrow [Chevron] deference”).

This doctrinal and normative perspective, however, risks missing much of what is important about the Chevron story. To really understand Chevron—where it came from, why it exists, and why it is fading—we need to view it through a positive political theory lens. This Part builds on recent work in this vein to situate Chevron in politics, and it argues that Chevron is, and always was, politically contingent. In other words, Chevron is one possible solution to an endemic political problem in our separation-of-powers system.

A.      Political Origins

It has become increasingly clear that Chevron deference was politically constructed at a precise moment in time when pivotal parties deemed it advantageous for their purposes.¹⁷Of course, deference—as a practice rather than a doctrine with a name—was with us long before Chevron. See Brief of Scholars of Administrative Law & the Administrative Procedure Act as Amici Curiae in Support of Respondents at 10–16, Loper Bright Enters. v. Raimondo, 143 S. Ct. 2429 (filed Sept. 22, 2023) (No. 22-451) (collecting sources confirming that deference as a practice existed at the time of the passage of the Administrative Procedure Act (“APA”)). First, as Professor Craig Green describes, “[i]n the 1980s, Republican conservatives used administrative deference to roll back federal power without amending federal statutes,” and they could do so because deference took statutory interpretation partly out of the hands of “liberal judges” and put it in the hands of “deregulatory bureaucrats.”¹⁸Green, supra note 10, at 622. Normally, bureaucrats are not deregulatory, but the 1980s saw the Reagan Revolution, a major part of which involved the Reagan administration’s efforts to seize control of the administrative state and bend it toward deregulatory purposes.¹⁹See generally Thomas O. McGarity, Regulatory Reform in the Reagan Era, 45 Md. L. Rev. 253 (1986) (conveying the forces of the Reagan administration in regulatory reform); Marissa Martino Golden, What Motivates Bureaucrats? Politics and Administration During the Reagan Years (2000) (describing “bureaucratic behavior” during Reagan’s presidency); Richard A. Harris & Sidney M. Milkis, The Politics of Regulatory Change: A Tale of Two Agencies (1989) (contrasting the “social regulation” of the 1970s and the deregulation of the Reagan administration in the 1980s). These changed political circumstances fundamentally flipped the conservative position on deference.²⁰Elinson & Gould, supra note 10, at 480 (discussing the Bumpers Amendment—a piece of legislation supported by conservative forces in the 1970s—which would have eliminated deference to agency decisions a decade before Chevron, and the reversal of position after the Chevron decision). The notoriously liberal Court of Appeals for the D.C. Circuit (and, to some extent, the more moderate Supreme Court) acted as the main roadblock to deregulation during the Reagan years,²¹See Harry T. Edwards, Public Misperceptions Concerning the “Politics” of Judging: Dispelling Some Myths About the D.C. Circuit, 56 U. Colo. L. Rev. 619, 622–23 (1985) (collecting contemporaneous sources that describe the Court of Appeals for the D.C. Circuit as liberal, but disagreeing with that interpretation). so it made perfect sense for movement conservatives at the time to support a doctrine that pried power from ideological opponents in the judiciary and placed it with ideological allies in the executive branch. Justice Antonin Scalia was shockingly transparent about these goals.²²Elinson & Gould, supra note 10, at 511 (quoting then-Professor Antonin Scalia  as saying, congressional Republicans “seem perversely unaware that the accursed ‘unelected officials’ downtown are now their unelected officials, presumably seeking to move things in their desired direction; and that every curtailment of desirable agency discretion obstructs (principally) departure from a Democrat-produced, pro-regulatory status quo”). Although it may surprise modern readers used to concerted attacks on Chevron from the political right, the doctrine initially was very much driven early on by Republican politicos who confidently predicted the triumph of Republican presidential politics in the wake of Reagan.²³See Merrill, supra note 10, at 84 (“The Chevron doctrine, once it got going, was likewise regarded for some time as a ‘conservative’ doctrine, given its association with the Reagan Administration’s deregulation efforts and strenuous advocacy of the doctrine by Justice Scalia.”).

Second, the nascent Chevron doctrine also received a boost from a strange bedfellow—Judge Patricia Wald of the Court of Appeals for the D.C. Circuit.²⁴Id. at 85. As Professor Thomas Merrill argues, Wald attempted to articulate and elevate the doctrine—specifically, the two-step framework—to thread the needle in certain environmental cases, supporting “a sensible, if legally questionable, EPA interpretation” in one case while “preserving a significant degree of discretion for courts to overturn decisions regarded as less sensible” at step two of the doctrine.²⁵Merrill argues that Judge Wald was perhaps motivated by a short-term interest in achieving a lasting reversal of certain environmental opinions by the Court of Appeals for the D.C. Circuit that vacated EPA rules that had attracted both liberal and conservative judges to statutory interpretations that reflected the “most plausible reading.” Id. at 84–85. On this account, Judge Wald adapted Chevron’s two-step framework to thread the needle in these cases, using it as a “device to justify a sensible, if legally questionable EPA interpretation in General Motors” while also using it in Rettig to “preserv[e] a significant degree of discretion for courts to overturn decisions regarded as less sensible.” Id. at 85. As Merrill notes, “If this is indeed where the seeds of ‘the Chevron doctrine’ were planted, it suggests that a large part of its appeal [to Wald] was that it enhanced the discretion of judges to accept or reject particular agency interpretations based on the nebulous requirements of ‘clarity’ and ‘reasonableness’—free from the encrustations of traditional doctrine.” Id. Although Judge Wald was a Democratic appointee who likely did not share Justice Scalia’s policy preferences in any way,²⁶Cf. Richard L. Revesz, Environmental Regulation, Ideology, and the D.C. Circuit, 83 Va. L. Rev. 1717, 1718–19 (1997) (arguing that the party of the appointing President is an acceptable proxy for the ideology of court of appeals judges). she worked behind the scenes to elevate Chevron into the doctrine that we now recognize.²⁷Merrill, supra note 10, at 85. By articulating an ostensibly liberal reason for supporting Chevron, Judge Wald helped solidify the judiciary’s embrace of the doctrine in the face of the Reagan Revolution. As it turned out, Judge Wald miscalculated: in subsequent deployments of the doctrine, the courts elevated the step-one inquiry into a stringent statutory interpretation exercise and turned the step-two inquiry into a rote exercise of arbitrariness review.²⁸See Ronald M. Levin, The Anatomy of Chevron: Step Two Reconsidered, 72 Chi.-Kent L. Rev. 1253, 1265 (1997). But see Kent Barnett & Christopher J. Walker, Chevron Step Two’s Domain, 93 Notre Dame L. Rev. 1441, 1452–57 (2018) (finding that many circuit courts follow the arbitrary and capricious test but many also apply a hyper-purposivist analysis). Over time, the two-step doctrine that Wald believed would give liberal judges power to resist deregulatory policies emanating from deregulatory presidential administrations ended up crystallizing into a more categorical rule of deference, provided the statute’s interpretation did not resolve the case.²⁹Kent Barnett & Christopher J. Walker, Chevron in the Circuit Courts, 116 Mich. L. Rev. 1, 32–34 (2017). By the time that evolution was complete, however, the Reagan Revolution had passed, giving way to a period of unexpectedly close partisan competition for the presidency.³⁰The competition has been close both in the sense that elections themselves have often been close—as in the nailbiters of 2000, 2016, and 2020—but also in the sense that Democratic and Republican candidates have evenly split victories in the six elections since 2000. See Statistics, Am. Presidency Project, perma.cc/89UG-MMBL. The stark partisan stakes of the doctrine consequently became more fuzzy.³¹See infra Part III. As a result, Chevron solidified itself as a relatively uncontroversial fixture of administrative law preserved more or less by inertia for almost two decades.³²Elinson & Gould, supra note 10, at 480 (noting that the Chevron doctrine experienced “two decades of relative quiescence in the 1990s and 2000s”).

What can we learn from this? Most important for present purposes is that the Chevron doctrine was born of political calculation. Overall, Chevron emerged when it did and how it did because of predictions about the likely configuration of the political terrain around regulation. At root, Chevron was an answer to a salient question of interbranch political power-sharing presented at a pivotal moment in time—namely, when a long-standing alignment of the branches changed in a seemingly lasting way, leading judges to recognize the advantages of a doctrinal reconfiguration. The birth of Chevron also highlights the uncertainty of this kind of political response and the risks of strategic miscalculation—Judge Wald may have won several battles, but she did not win the war, at least if the goal was to protect judicial power against encroachment by bureaucrats. And Justice Scalia was similarly wrong about the durability of the Reagan Revolution. Finally, the episode underscores the inertial quality of regime politics. Once a new doctrinal configuration solidifies, it can last for quite a while—at least until a major policy shock upsets that configuration or until pivotal actors’ understanding of the strategic terrain has time to update.³³For helpful background on how social scientists think about political change over time, and in particular how change is sporadic and rapid, see generally Frank R. Baumgartner & Bryan D. Jones, Agendas and Instability in American Politics (1993) (articulating a theory of “punctuated equilibrium” in which periods of stasis (equilibria) are upset at inflection points, often fomented by policy activism or new ideas, and replaced by new arrangements that are themselves likely to last for some time); Paul Pierson, Politics in Time: History, Institutions, and Social Analysis (2004) (highlighting the importance of the “temporal dimension” of politics more generally).

B.      Political Erosion

As discussed above, after an overtly political beginning, Chevron deference became a fixture of administrative law for about two decades. During this period, judges appointed by presidents of both parties invoked Chevron without much concern about the doctrine.³⁴To be sure, internecine fights over particular policies led Chevron to be applied in ways that statistically evinced partisan biases. See Thomas J. Miles & Cass R. Sunstein, Do Judges Make Regulatory Policy? An Empirical Investigation of Chevron, 73 U. Chi. L. Rev. 823, 831 (2006). But see Barnett & Walker, supra note 29, at 28–44 (showing that this pattern was not as apparent in the circuit courts). This period also saw some limitations on “Chevron’s domain,” Merrill & Hickman, supra note 15, at 838–48, namely in the Christensen, Mead, and Barnhart cases, but was also matched by some expansions, such as in the Brand X case. See Bressman, supra note 15, at 1475–77. That period of apparent consensus might at first glance give the appearance that Chevron had become de-politicized.³⁵As I discuss below, it would be a mistake to read the evidence of cross-partisan application of Chevron in the 1990s and 2000s as evidence that undermines a political explanation of Chevron. Political scientists have long recognized that the crudest form of the “attitudinal model”—that judges vote on a case-by-case basis according to their political priors—is an incomplete model of judicial decision-making. See, e.g., Donald R. Songer, The Dog that Did Not Bark: Debunking the Myths Surrounding the Attitudinal Model of Supreme Court Decision Making, 33 Just. Sys. J. 340 (2012) (collecting critiques of the attitudinal model). Nobody would expect judges to oscillate violently between deference and anti-deference based solely on the political stakes of the individual cases in front of them; rather, as I show in Part II, the Justices are more likely to make strategic decisions about the optimal deference doctrine in light of their predictions of the likelihood that they will be sympathetic or opposed to the average case that comes before them over a period of time. Factoring in long-range strategy and uncertainty complicates any effort to paint ostensibly apolitical application of Chevron as a triumph for the “legal model,” as it could be, and likely was, the case that the 1990s and 2000s were simply a period of high uncertainty about key variables in a strategic approach to choosing whether to displace the Chevron status quo. See infra Section II.B. Over the last ten to fifteen years, however, any illusion of Chevron’s cross-partisan political support has clearly eroded.³⁶Cass R. Sunstein, Chevron as Law, 107 Geo. L.J. 1613, 1617 (2019) (“Chevron has become the flashpoint for contemporary concerns over the power and the legitimacy of the modern administrative state.”); id. at 1618 (“A remarkable shift, to which I shall devote some attention, involves Chevron’s political valence—that is, the perceived connection between Chevron and identifiable sets of political convictions. Once celebrated by the right and sharply criticized by the left, Chevron is now under assault from the right and (for the most part) accepted on the left.”). Whatever happens in Loper Bright and Relentless, most observers predict that the Justices’ votes will align with their partisan identification, with some combination of the conservative Republican appointees voting to end or significantly curtail Chevron deference.³⁷See, e.g., Ian Millhiser, A New Supreme Court Case Seeks to Make the Nine Justices Even More Powerful, Vox (May 2, 2023, 7:30 AM), https://perma.cc/5H59-DYRK. In fact, some observers believe that the Court has already effectively abandoned Chevron without saying so. See, e.g., Lisa Heinzerling, How Government Ends, Bos. Rev. (Sept. 28, 2022), https://perma.cc/RGC4-CNRB.

It would be tempting for lawyers to chalk up this radical change in the political valence of Chevron, and the resulting instability of Chevron deference, to ideas and first principles. On this account, more conservative jurists have simply awakened to the mistakes of Justice Scalia in supporting a doctrine that fundamentally recalibrates the separation of powers or undermines due process,³⁸Jack M. Beermann, End the Failed Chevron Experiment Now: How Chevron Has Failed and Why It Can and Should Be Overruled, 42 Conn. L. Rev. 779, 795–96 (2010) (nodding to separation of powers concerns with Chevron); Philip Hamburger, Chevron Bias, 84 Geo. Wash. L. Rev. 1187, 1209–10 (2016) (arguing that Chevron undermines due process of law by causing judges to exercise something less than “independent judgment”). while liberals and progressives have come to believe that Chevron protects cross-ideological values, like agency expertise.³⁹See, e.g., Sidney Shapiro & Elizabeth Fisher, Chevron and the Legitimacy of “Expert” Public Administration, 22 Wm. & Mary Bill Rts. J. 465 (2013) (asserting “[e]xpertise is central to the deference required by Chevron”). There certainly has been no shortage of work done in recent years to build an ostensibly legal foundation for deconstructing many aspects of the administrative state, starting with Chevron.⁴⁰Elinson & Gould, supra note 10, at 529 (noting that a “new set of actors came onto the scene between the 1970s and 2010s: ideological conservatives,” and concluding that “this ‘new class’ of libertarian-leaning conservatives . . . expressed hostility to the regulatory state’s very existence”). This project hardly stops with eliminating or limiting Chevron; it also entails limiting the independence of agencies from presidential oversight and curbing Congress’s ability to delegate power to agencies in the first place.

This apolitical and doctrinal explanation of Chevron dissensus misses too much. There is no real way to explain why smart conservative lawyers, who would have been well aware of early criticisms of Chevron as a “counter-Marbury for the administrative state,”⁴¹Cass R. Sunstein, Beyond Marbury: The Executive’s Power to Say What the Law Is, 115 Yale L.J. 2580, 2589 (2006); Cynthia R. Farina, Statutory Interpretation and the Balance of Power in the Administrative State, 89 Colum. L. Rev. 452, 478–80 (1989). You cannot be more explicit about this than Justice Scalia was. Antonin Scalia, Judicial Deference to Administrative Interpretations of Law, 1989 Duke L.J. 511, 513 (1989) (“[O]n its face [Chevron] seems quite incompatible with Marshall’s aphorism that ‘[i]t is emphatically the province and duty of the judicial department to say what the law is.’”). would have accepted deference for so long, only to snap out of it just recently. Nor is it possible to explain why liberals and progressives have rallied around Chevron deference despite overwhelming evidence that Chevron allows for as much deregulation as regulation,⁴²Professor Jonathan Masur’s contribution to this symposium makes this point quite effectively—Chevron’s valence is entirely driven by the agency actions that it is applied to, and therefore neither inherently deregulatory nor inherently pro-regulatory. Jonathan S. Masur, Loper Bright as Entrenchment, 30 Geo. Mason L. Rev. 573, 574 (2024); see also Pamela King, How SCOTUS Gutting Chevron Could Haunt Republicans, E&E News (May 16, 2023, 1:26 PM), https://perma.cc/9K5U-WZS3. and indeed was forged for that very purpose.⁴³See supra Section I.A. Chevron’s politics have flip-flopped and become entrenched in recent years, but these trends have little to do with legal principles and far more to do with changing political circumstances.

Recent scholarly accounts that center the politics of Chevron have helped us begin to unpack why the astonishing change in Chevron’s political valence over the past ten to fifteen years actually occurred. Professors Jonathan Gould and Gregory Elinson point to a conservative backlash against a surge of rulemaking by administrative agencies during the Obama administration, all of which “increased Chevron’s overall salience” and highlighted the ways that Chevron could support an ambitious progressive regulatory agenda.⁴⁴Elinson & Gould, supra note 10, at 524, 525–30. Thomas Merrill, while highlighting essentially apolitical concerns about the functionality of the doctrine,⁴⁵Merrill, supra note 10, at 257–61. also acknowledges conservative backlash against President Barack Obama’s regulatory policy as a core driver of Chevron’s current “crisis of legitimacy.”⁴⁶Id. at 1. Professor Craig Green points to “personnel shifts in the judiciary” and to “broader ideas about the ‘deconstruction of the administrative state’” that became more mainstream in just the last decade or so.⁴⁷Green, supra note 10, at 622 (citation omitted). These explanations no doubt capture much of the story.

Still, there is something puzzling about the shifting terrain. Were simple backlash the whole story, one might have expected positions to flip again once President Donald Trump assumed office and began aggressively pursuing a deregulatory agenda.⁴⁸Elinson & Gould, supra note 10, at 531. Yet that is not what happened.⁴⁹See James Kunhardt & Anne Joseph O’Connell, Judicial Deference and the Future of Regulation, Brookings (Aug. 18, 2022), https://perma.cc/93C3-PUM2 (noting that the Trump administration often declined to request Chevron deference in its briefing in statutory interpretation cases involving agencies, and that the Court has not applied Chevron since 2016). Explaining this “dog that didn’t bark” moment might tempt us to fall back on legal explanations, but, again, these stories cannot explain why Chevron’s political valence shifted so drastically. And while the composition of the federal judiciary (in particular, the Supreme Court) surely matters a great deal, what are we to make of the fact that Republican-appointed Justices have long had a solid majority but have apparently hesitated to roll back deference entirely despite opportunities to do so?⁵⁰See, e.g., Buffington v. McDonough, 143 S. Ct. 14, 14 (2022) (denying certiorari over a dissent by Justice Neil Gorsuch); Kisor v. Wilkie, 139 S. Ct. 2400, 2418 (2019) (declining to do away with Auer deference on account of stare decisis). Clearly, a reductive attitudinalist account that centers only the Justices’ contemporary political preferences misses something important that pushes toward more stasis in the law.

In short, there is much that we do not understand about what truly drives the perennially shifting debates about Chevron. That lack of understanding hampers our ability to predict what might happen next.

II.      Modeling Chevron’s Political Contingency

Both scholarship and practice would benefit from a greater understanding of Chevron’s enduring political dynamics. In this Part, I contribute to this endeavor by laying out a simple positive political theory model that captures the core insights of the emerging literature on the politics of Chevron deference. This is an important project because, while the political contingency of Chevron is a reality and should “give us pause before telling deterministic stories about the past and make us more hesitant to offer predictions concerning the future,”⁵¹Elinson & Gould, supra note 10, at 536. there may be some things that are relatively predictable about the future of deference. Models necessarily simplify, but, precisely because of that, they can reveal the political logic that really drives change, providing both parsimonious explanation of the past and predictions for the future.⁵²For general background on models and their uses, see Kevin A. Clarke & David M. Primo, Modernizing Political Science: A Model-Based Approach, 5 Persp. on Pol. 741, 741–44 (2007). I do not mean to do anything more than invoke a general, informal modeling approach here, though much political science research employs more complex, mathematical models that trade off on parsimony for greater accuracy.

The chief assumption my simple model makes, which will be familiar to political scientists but perhaps not as familiar (or acceptable) to lawyers, is that judges are policy preference maximizers—they seek to decide cases, and to decide among doctrinal means of deciding cases, based on their beliefs about how different options will benefit the realization of political goals they may have.⁵³See generally Tom S. Clark, The Supreme Court: An Analytic History of Constitutional Decision Making (2019) (discussing political science research, which often argues or assumes that judges are political actors but also shows that many factors besides pure outcome-driven considerations (e.g., strategic considerations) may structure judicial politics). Of particular relevance here is a body of work in political science—dubbed the “new judicial politics of legal doctrine”—that acknowledges the role that legal doctrines play in the politics of judicial decisionmaking. See Jeffrey R. Lax, The New Judicial Politics of Legal Doctrine, 14 Ann. Rev. Pol. Sci. 131, 134–35 (2011). This work harmonizes “attitudinal” or “strategic” models of judicial decisionmaking with evidence that, at least at times, precedent and doctrine do seem to constrain judges. See Mark J. Richards & Herbert M. Kritzer, Jurisprudential Regimes in Supreme Court Decision Making, 96 Am. Pol. Sci. Rev. 305, 315–16 (2002). If judges are voting for doctrinal frameworks that will govern future disputes, they are still making policy-oriented decisions but in a legal register familiar to lawyers. The model I offer picks up on the questions that are left over after this recognition that doctrine is the object of politics: What drives change of legal doctrines? Work on this question is in its infancy. See generally, e.g., Brandon L. Bartels & Andrew J. O’Green, The Nature of Legal Change on the U.S. Supreme Court: Jurisprudential Regimes Theory and Its Alternatives, 59 Am. J. Pol. Sci. 880 (2015) (reorienting the debate over “legal change and constraint”). The second assumption  the model makes is that judges prefer to minimize their workload in doing so—that is, all else equal, judges would prefer to exert less effort to realize their policy goals.⁵⁴Richard A. Posner, What Do Judges and Justices Maximize? (The Same Thing Everyone Else Does), 3 Sup. Ct. Econ. Rev. 1, 3–5, 39–41 (1993).

In non-agency cases presenting statutory interpretation questions, the prescription for judges is clear: judges should invest as much effort as they feel necessary to support their decisions in a credible, public-facing way. In agency cases, however, judges have a potential shortcut—namely, agencies may provide the work to defend a particular policy outcome, and if that policy aligns with what the judge would have chosen, then the need for independent exertion is eliminated.⁵⁵Cf. Tonja Jacobi & Emerson H. Tiller, Legal Doctrine and Political Control, 23 J.L. Econ. & Org. 326, 327 (2007) (outlining a model of hierarchical control of the lower courts by a higher court that similarly relies on the higher court’s ability to rely on lower courts to reach similar results and which counsels use of rules to constrain lower courts when there is risk of slack). Moreover, judges might be able to hide behind the apparent neutrality of doctrine requiring deference to legitimize their policy-driven rulings if the doctrinal prescription fortuitously coincides with the judge’s own preferences for the resolution of cases.⁵⁶Kent Barnett, Christina L. Boyd & Christopher J. Walker, The Politics of Selecting Chevron Deference, 15 J. Empirical Legal Stud. 597, 601 (2018) (noting that, by choosing to deploy Chevron deference, judges may be able to “align the outcome with their policy preferences” and “shroud their chosen outcome under the cover of neutral principles of judicial review that appear independent from the merits”). Thus is born the possibility of Chevron deference.

A.      Two Driving Factors

The problem with the shortcut is that agencies do not always produce policies aligning with judicial preferences because the policy visions of presidential administrations do not always align with judicial preferences. Consequently, a judge who wishes to take advantage of the shortcut will want to do so only selectively—that is, only when the policies promulgated by the agency are likely to align with judicial preferences. Otherwise, if agency policies do not align with judicial preferences, the shortcut (while saving judges effort) will start to cost judges in terms of maximization of their preferences, and judges would, all things considered, prefer to exert the effort necessary to independently justify their policy preferences. Just as bad is the reverse possibility: if agency policies generally align with a judge but the judge has elected to do away with deference, that judge will have to work harder to uphold agency action that they could have approved with little effort under a deference doctrine. A judge that realizes all of this would consider, if only implicitly, two key factors in deciding whether the prevailing doctrine should default to deference or default to judicial review.

First, a judge would look at their general allyship with the executive branch, as allyship would indicate that first moves by the agency will usually align with the judge’s preferences.⁵⁷Elinson & Gould, supra note 10, at 538 (“It stands to reason, then, that a party with control over the executive branch but facing an unfriendly judiciary would favor Chevron. Conversely, a party that does not control the White House but has a sympathetic Supreme Court (or, secondarily, D.C. Circuit) would take the reverse position.”). While there are many determinants of agency decision-making, in an era of “presidential administration,”⁵⁸Elena Kagan, Presidential Administration, 114 Harv. L. Rev. 2245, 2250–51 (2001). the best indicator of allyship is the partisanship of the President. To be sure, there are probably many agencies where this assumption is not reliable. Independent agencies, for instance, are more likely to promulgate policies that depart from the sitting President’s preferences.⁵⁹David E. Lewis & Jennifer L. Selin, Political Control and the Forms of Agency Independence, 83 Geo. Wash. L. Rev. 1487, 1490, 1514 (2015). Likewise, some agencies have unique cultures and political identities that might make it more difficult for Presidents of certain parties to shape policy.⁶⁰Joshua D. Clinton, Anthony Bertelli, Christian R. Grose, David E. Lewis & David C. Nixon, Separated Powers in the United States: The Ideology of Agencies, Presidents, and Congress, 56 Am. J. Pol. Sci. 341, 352 (2012). But, overall, Presidents are likely to get their way, especially on the most significant policymaking initiatives and the ones that judges would care the most about.⁶¹Kenneth Lowande, Politicization and Responsiveness in Executive Agencies, 81 J. Pol. 33, 45 (2018). This makes the President’s preferences a decent proxy for judges who want to predict allyship and, by extension, the utility of Chevron.

Second, a judge would consider the certainty of their prediction of future allyship or opposition.⁶²The positive political theory literature gives close attention to these factors, recognizing that long-range predictions about electoral competition and future allyship can shape strategic incentives of lawmakers. See, e.g., Rui J. P. de Figueiredo, Jr., Electoral Competition, Political Uncertainty, and Policy Insulation, 96 Am. Pol. Sci. Rev. 321, 330–31 (2002) (examining the role of uncertainty about electoral competition in decisions by Congress to structure the administrative state to either be insulated or subject to greater political control). Because judges craft doctrine that presumptively should not be reversed every four years (this would probably look unseemly and would potentially risk institutional delegitimization or at least substantial political pushback), judges cannot precisely tailor the deference regime to the sitting President. Instead, judges are likely to try to make a prediction about what party will control the White House for some period of time and to select a doctrinal approach that maximizes the average policy payoff across multiple administrations—perhaps for a judge’s entire career. At the same time, because judges are not oracles, they will need to discount their predictions to account for uncertainty, particularly the further into the future the judge wants to try to predict the average political configuration.⁶³There is a robust debate between rational actor models, which assume low levels of uncertainty, and bounded rationality models, which do not. See generally Bryan D. Jones, Politics and the Architecture of Choice: Bounded Rationality and Governance (2001) (characterizing the debate using formal complex institutions, like government agencies).

B.      The Complete Model

The two key factors in our model can be combined to create a two-by-two contingency table (see Table 1 below). The upshot of this exercise is that high levels of certainty about future allyship will likely lead to judges taking a strong stance in favor of a rule-like approach (either pro-deference or anti-deference), depending on whether the prediction is for future allyship or future opposition. All else equal, a judge who feels certain about the future will make a relatively undiluted decision on whether the shortcut is advantageous and craft doctrine accordingly, while a judge uncertain about the future will resort to strategies to mitigate risks of mistake while still acting in accordance with the dominant strategy vis-à-vis the executive branch—for instance, by endorsing doctrinal formulations that preserve greater flexibility for judges to toggle in or out of deference. On the margins, a judge uncertain of the future but predicting allyship might begin carving out specific exceptions to Chevron that would allow judges to selectively deploy the shortcut. By contrast, a judge uncertain of the future but predicting opposition might favor a more across-the-board deployment of Skidmore respect that allows the judge to refuse to defer to the agency’s interpretation if necessary but contains enough flexibility to allow the judge to point to the agency’s comparative expertise to obviate the need for an independent judgment call by the court.⁶⁴See Barnett et al., supra note 56, at 601–02 (discussing the political utility of being able to elect out of Chevron’s framework on more of a case-by-case basis).

Table 1: Modeling Optimal Deference Doctrines

	Future Allyship with Presidents	Future Opposition with Presidents
High Certainty	Strong Deference (e.g., Chevron)	Strong Anti-Deference (e.g., de novo review)
Low Certainty	Weak Deference (e.g., Chevron but with exceptions)	Weak Anti-Deference (e.g., Skidmore respect)

There is, of course, much that this model leaves out. For instance, it is likely that concerns about control of lower courts’ discretion in implementing doctrine marginally affect these choices.⁶⁵Much political science modeling of doctrine looks at the difficulties of control of lower courts as a key variable for determining whether, for instance, to formulate doctrine as a rule or a standard. See, e.g., Jacobi & Tiller, supra note 55, at 326–27. This variable may be less important in light of the Supreme Court’s increasing use of the shadow docket to police lower court decisions. See generally Stephen Vladeck, The Shadow Docket: How the Supreme Court Uses Stealth Rulings to Amass Power and Undermine the Republic (2023). A more complicated model might also factor in Congress’s preferences.⁶⁶See, e.g., Virginia A. Hettinger & Christopher Zorn, Explaining the Incidence and Timing of Congressional Responses to the U.S. Supreme Court, 30 Leg. Stud. Q. 5, 7 (2005); John A. Ferejohn & Barry R. Weingast, A Positive Theory of Statutory Interpretation, 12 Int’l Rev. L. & Econ. 263, 267–69 (1992). Yet even this simple model maps fairly clearly, and powerfully, onto the available options for judges confronting choices about how to design deference doctrine for the long haul. The model also seems to fit the data we have reasonably well.

First, as discussed above, Chevron arose at a pivotal moment in American political history when it seemed to the more conservative Justices that future allyship with the executive branch was relatively likely.⁶⁷See supra Section I.A. That confidence faded slightly in a subsequent era of fierce partisan competition for the presidency, resulting in more doctrinal hedging by the Court.⁶⁸See supra note 30 and accompanying text. But, overall, the core of Chevron (as modified by Mead and similar cases) survived for as long as it did because of this competition—”hope springs eternal.”⁶⁹Alexander Pope, An Essay on Man, 5 (1734).

Second, the model can help make sense of the current political terrain and the puzzling ossification of views of Chevron even amidst the rapid changes of control of the White House over the past sixteen years. President Obama’s 2008 election and subsequent reelection was widely recognized as transformative and threatening to Republicans’ long-term prospects for taking control of the White House.⁷⁰See, e.g., Alan I. Abramowitz, Transformation and Polarization: The 2008 Presidential Election and the New American Electorate, 29 Elec. Studs. 594, 596–99 (2010) (discussing factors in the 2008 presidential election that “are likely to affect elections for many years to come”). Indeed, it was not until Donald Trump shocked the world in 2016 that we stopped hearing so much about the “demographics as destiny” argument that Democrats would dominate the presidency for the foreseeable future.⁷¹For discussion of the “demographics as destiny” hypothesis, see Philip Elliott, Are Demographics Destiny? Maybe Not, New Pew Numbers Suggest, Time (June 30, 2021, 2:02 PM), https://perma.cc/NG7A-KH85. For a particularly robust statement of confidence in this thesis, see James Carville with Rebecca Buckwalter-Poza, 40 More Years: How Democrats Will Rule the Next Generation 31–35 (2011). This prediction was overstated—it turns out that demographic change does not uniformly benefit Democrats,⁷²Elliott, supra note 71. and the electoral college gives Republican candidates a (small) counterweight to any demographic advantage for Democrats⁷³David Leonhardt, Is the Electoral College Becoming Fairer?, N.Y. Times (Sept. 12, 2023), https://perma.cc/Z9SP-793G (acknowledging that the “Electoral College has been very kind to Republicans in the 21st century,” but that “over the past few years the Republican advantage in the Electoral College seems to have shrunk”).—but it would probably be a mistake to overcorrect predictions. The smart money remains with Presidents being more often Democratic than Republican for the foreseeable future due to a strong popular vote advantage,⁷⁴David A. Walker, Forecasting the 2020 and 2024 U.S. Presidential Elections, 42 J. Forecasting 1519, 1528 (2023) (predicting a 53.7% popular vote favoring an unnamed Democratic candidate in 2024). generally favorable (if somewhat unpredictable) demographic trends,⁷⁵Robert Griffin, Ruy Teixeira & Wiliam H. Frey, America’s Electoral Future: Demographic Shifts and the Future of the Trump Coalition 14 (2018). as well as an increasingly fractured Republican Party.⁷⁶Samuel L. Popkin, Crackup: The Republican Implosion and the Future of American Politics 3 (2021). As I write, the Republican Party has just finished several weeks of infighting over its leadership in the House, prompting calls for a “break up” among its warring coalitions. See Max Burns, Opinion, End of an Era: It’s Time for the Republicans to Break Up, Hill (Oct. 25, 2023, 10:00 AM), https://perma.cc/VV94-WCGD. Meanwhile, little doubt exists that the Supreme Court, and indeed the courts generally, are as ideologically conservative, and therefore as aligned with the Republican coalition, as they have been for some time.⁷⁷Stephen Jessee, Neil Malhotra & Maya Sen, A Decade-Long Longitudinal Survey Shows that the Supreme Court Is Now Much More Conservative than the Public, 119 Proc. Nat’l Acad. Sci. 1, 2 (2022); see also April Rubin, Supreme Court Ideology Continues to Lean Conservative, New Data Shows, Axios (July 3, 2023), https://perma.cc/43S2-HYM8. Comprehensive quantitative metrics on the ideological composition of the lower courts are harder to come by, but currently there are more judges appointed by Republican Presidents than Democratic Presidents in the courts of appeals (but not the district courts). See Circuit Status, Balls & Strikes (Jan. 4, 2024, 10:48 AM), https://perma.cc/S8PH-825J. Subject-matter specific studies of voting patterns suggest that Trump-appointed judges in the lower courts are indeed distinctively conservative. See, e.g., Stephen J. Choi, Mitu Gulati & Eric A. Posner, Trump’s Lower-Court Judges and Religion: An Initial Appraisal 2–3 (Pub. L. & Legal Theory, Rsch. Paper No. 2023-49, 2023). Given life tenure and the age of many recent nominees to the courts, there is little reason to think this configuration on the Court or the courts in general will change any time soon.⁷⁸Adam Chilton, Dan Epps, Kyle Rozema & Maya Sen, The Endgame of Court-Packing 2 (May 4, 2023) (unpublished manuscript) (on file with the George Mason Law Review) (conducting a simulation exercise and finding that, without a court-packing event, it would take on average forty-four years for a 3-6 minority on the Supreme Court to reclaim a majority).

It is no surprise, then, that the Court’s most conservative Justices began changing their tune on Chevron in recent years—deference on average could be plausibly forecasted to favor a pro-regulatory agenda offered by Democratic Presidents. A one-term, and largely ineffectual, Trump presidency, followed by election of another Democratic President in Joe Biden, has only reinforced these concerns among conservatives.⁷⁹See, e.g., Amy Gunia, Republicans Are Divided on Trump’s Third Bid for the Presidency, Time (Nov. 16, 2022, 1:45 AM), https://perma.cc/64W9-2M2G; Editorial Board, Opinion, The 2024 Republican Choice, Wall St. J. (Jan. 21, 2024, 5:56 PM), https://perma.cc/JVE7-J7G7. It would not be unreasonable for the Court’s conservative majority to shift to a prediction that deference, on average, will not benefit them in realizing their policy goals, given that it is more likely that Presidents will be opponents for the foreseeable future.

What remains to be seen, and what will likely be answered in the Loper Bright and Relentless cases, is how confident the conservative Justices are about this prediction. The answer to that question could well determine whether the Court decides to scrap Chevron altogether or whether it simply limits the doctrine.

III.      Assessing the Four Possible Futures of Chevron

So far, we have focused on the past and present, but one advantage of trying to distill Chevron’s politics down to a parsimonious model is that it can, if it is at all valid, provide tentative insights about the future. In this Part, I ask what political science work relevant to the variables in the model offered above could teach a curious Justice—the Justice who has not made up their mind about whether they predict future allyship or future opposition, and whether they are confident or uncertain about that prediction. Of course, it is somewhat fanciful to think that Justices would consider this kind of information in making their assessments, although maybe they should. After all, we have already seen that jurists make mistakes in reading the political future,⁸⁰See supra Section I.A. and it does not seem implausible that overly confident members of the Supreme Court’s current conservative coalition will box themselves in unnecessarily by assuming too quickly that Democrats will dominate the White House and doing away with the useful device of Chevron. But don’t let them say they weren’t warned.

One insight that emerges from this exercise is that Chevron (with or without exceptions) is a dominant strategy for preference-maximizing Justices, given longstanding patterns of regime politics. The recent erosion of support for Chevron and embrace of anti-deference by some of the Justices are, in part, attributable to anomalous political circumstances that raise, for the first time in the Chevron era, the distinct possibility that the Court will be persistently at odds with a dominant lawmaking coalition. These conditions, though, will almost certainly revert to normalcy in the long run. This does not guarantee Chevron deference will return to us regardless of what happens this term, but it does come close. Perhaps more important in the short run, these considerations suggest that, on balance, it would be smart for the Court to hedge its bets and decline to discard deference entirely in the Loper Bright and Relentless cases.

A.      The Court-President Relationship in Historical Perspective

In 1957, the political scientist Robert Dahl observed that “the policy views dominant on the [Supreme] Court are never for long out of line with the policy views dominant among the lawmaking majorities of the United States.”⁸¹Robert A. Dahl, Decision-Making in a Democracy: The Supreme Court as a National Policy-Maker, 6 J. Pub. L. 279, 285 (1957). At the time, Professor Dahl was pushing back against the idea, popular among law professors, that the Supreme Court was a counter-majoritarian institution by its very nature. ⁸²Mark A. Graber, The Nonmajoritarian Difficulty: Legislative Deference to the Judiciary, 7 Stud. Am. Pol. Dev. 35, 35 (1993). It was not, and to see why it was not, one needed to consider only that regular turnover on the Court could be expected, on average, to afford Presidents two nominations to the Supreme Court per term⁸³Lee Epstein, Jack Knight & Andrew D. Martin, The Supreme Court as a Strategic National Policymaker, 50 Emory L.J. 583, 586 (2001).—often enough to leave a major imprint on the institution. Especially in times of one-party dominance of the Presidency and of Congress, which historically have been the norm, this device for regular appointments virtually ensures that the Supreme Court will not be wildly out of step with the dominant lawmaking coalition. A large body of regime theory in American Political Development (“APD”) work demonstrates this basic pattern,⁸⁴See, e.g., Keith E. Whittington, Law and the Courts, in The Oxford Handbook of American Political Development 321 (Robert M. Valelly et al., eds., 2014); Thomas M. Keck, Party Politics or Judicial Independence: The Regime Politics Literature Hits the Law Schools, 32 Law & Soc. Inquiry 511, 519 (2007); George I. Lovell & Scott E. Lemieux, Assessing Juristocracy: Are Judges Rulers or Agents?, 65 Md. L. Rev. 100, 100 (2006); Kevin J. McMahon, Will the Supreme Court Still “Seldom Stray Very Far”?: Regime Politics in a Polarized America, 93 Chi.-Kent L. Rev. 343, 345 (2018); Dave Bridge & Curt Nichols, Congressional Attacks on the Supreme Court: A Mechanism to Maintain, Build, and Consolidate, 41 Law & Soc. Inquiry 100, 101 (2016). and more formalistic game theoretical models basically predict the same thing.⁸⁵See generally Epstein et al., supra note 83. Our constitutional system highly discourages a persistent divergence—the kind that would last for more than a few years here and there—between the Supreme Court and the President. If the pattern holds in the future, the implications for the model of Chevron offered above are clear: on balance, the Supreme Court should be more likely to view the President as a probable ally over the long haul. Any prediction of future opposition should be, in light of these longstanding and structural trends, naturally tentative.

To be sure, there are some who believe that the pattern may be breaking. Professors Paul Baumgardner and Calvin TerBeek, for instance, argue that Dahl’s regime theory desperately needs an update in a time where “our politics have become more conflictual and ideologically polarized” and where the Supreme Court has become “allied to a specific political project set forth by modern movement conservatism.”⁸⁶Paul Baumgardner & Calvin TerBeek, The U.S. Supreme Court Is Not a Dahlian Court, 36 Stud. Am. Pol. Dev. 148, 149 (2022). Baumgardner and TerBeek see a future where that movement “comes to thoroughly dominate American judicial politics,” and where a more persistent divergence between the Supreme Court and the President therefore emerges.⁸⁷Id.

There is surely something to the idea that the conservative legal movement has outmaneuvered opponents to build powerful machinery for the continued appointment of allies on the bench.⁸⁸See generally Robert O’Harrow Jr. & Shawn Boburg, A Conservative Activist’s Behind-the-Scenes Campaign to Remake the Nation’s Courts, Wash. Post (May 21, 2019), https://perma.cc/WJY8-GY26. For general background on the conservative legal movement, see generally Steven M. Teles, The Rise of the Conservative Legal Movement: The Battle for Control of the Law (2010); Amanda Hollis-Brusky, Ideas with Consequences: The Federalist Society and the Conservative Counterrevolution (2015). It is also probably true that the Supreme Court is currently, and historically, at odds with the dominant lawmaking coalition due to a series of fortuitous circumstances that gave Republican Presidents over the past twenty years more appointment opportunities than Democratic Presidents, despite a high degree of electoral competitiveness.⁸⁹See Daniel Hemel, Can Structural Changes Fix the Supreme Court?, 35 J. Econ. Persps. 119, 126–27 (2021) (examining the Court’s current crisis of legitimacy and locating it in a breakdown of the Dahlian pattern of regular replacement by the dominant lawmaking coalition). None of this, however, suggests that our current moment is anything but an outlier. The mechanics that have undergirded the Supreme Court’s regime politics for most of our history have not fundamentally changed. How Baumgardner and TerBeek’s break in regime theory is supposed to sustain itself going forward is unclear: for a thorough and persistent Republican domination of the Court to materialize, there would need to be a fairly significant run of Republican Presidents to stock the Supreme Court with reliable conservatives. But if that’s true, then it would also likely be true that the dominant lawmaking regime would be an ally, not an opponent, of the Court’s conservatives.

Moreover, one thing that regime theory teaches is that moments of counter-majoritarianism exist, often due to fortuitous historical circumstances, but when the Court asserts itself against a dominant lawmaking coalition, the results can backfire. One distinct possibility in the Chevron space is that a Court that chooses to act on a prediction of future opposition may foment a reaction from the elected branches. At the most extreme, the Court may risk the escalation of conflict into a court-packing plan that reduces the opposition between the branches. In other words, the allyship-opposition dimension of the model may be endogenous.

B.      The Unpredictability of American Political Competition in an Era of Polarization

Baumgardner and TerBeek are clearly right, though, that we live in an era of high partisan competition for the presidency and for control of government writ large.⁹⁰See also Frances E. Lee, Insecure Majorities: Congress and the Perpetual Campaign 1 (2016) (noting that recent years have featured “a ferocious power struggle for control of US national government,” but that “it has not always been so”). By the end of President Biden’s first term, the last twenty-four years will have seen twelve years of Republican Presidents and twelve years of Democratic Presidents. Arguably, this era of fierce competition extends even further back, to the beginning of the breakup of the dominant New Deal coalition in the 1970s or 1980s.⁹¹Daryl J. Levinson & Richard H. Pildes, Separation of Parties, Not Powers, 119 Harv. L. Rev. 2311, 2335 (2006). So close is the competition that “inversions”—that is, cases in which the popular-vote winner loses the election due to the electoral college—which have occurred only four times since 1836, have occurred twice since 2000.⁹²Michael Geruso, Dean Spears & Ishaana Talesara, Inversions in US Presidential Elections: 1836-2016, 14 Am Econ. J.: Applied Econ. 327, 329 (2022). While enough doubt may exist about the continuation of electoral competitiveness to at least raise the possibility that we are on the precipice of persistent domination of the presidency by the conservative Justices’ Democratic opponents,⁹³See supra notes 69–77 and accompanying text. it seems more likely that we will continue to experience high partisan competition for the presidency  for the foreseeable future.

These circumstances matter a great deal for the second dimension in the model offered above: the certainty or uncertainty of predictions. When the Justices make their long-range predictions about future allyship or opposition with the executive branch, the best evidence they have is likely to be current political conditions. If the Justices are anything like most people, they will use new information to update their prior beliefs about political facts, but will do so cautiously, favoring what they know about the present state of play.⁹⁴See Seth J. Hill, Learning Together Slowly: Bayesian Learning About Political Facts, 79 J. Pol. 1403, 1403 (2017); Lukas F. Stoetzer, Lucas Leemann & Richard Traunmueller, Learning from Polls During Electoral Campaigns, 46 Pol. Behav. 543, 544 (2022). Thus, uncertainty over the long run may follow from competition now, and it may take a substantial amount of time for this uncertainty to diminish. However, it cannot be ruled out that the Justices may not be normal—that is, that they update quicker than the average political observer, perhaps because of overconfidence. It seems like overconfidence, in part, led to the birth of Chevron,⁹⁵See supra Section I.A. which suggests that Chevron could also come undone because of overconfidence. Ultimately, it is difficult to know where the Justices stand on their predictions for future allyship or opposition, but an educated guess might be that they are likely to be relatively uncertain about their prediction for the foreseeable future. Under the model, this is conducive to retention of Chevron in diluted form.

What this might look like is anybody’s guess. The Court could decide in Loper Bright and Relentless to do nothing except restate existing limitations on Chevron’s domain, or to inveigh against lower courts’ sloppiness in applying Chevron’s two-step framework. The Court may well not need to do much more than this in light of the major questions doctrine. The major questions doctrine provides an ideal tool for the Court to limit Chevron while retaining its core, since so much will be determined by whether the Court believes agency action triggers the doctrine under currently quite manipulable criteria.⁹⁶See Todd Phillips & Beau J. Baumann, The Major Questions Doctrine’s Domain, 89 Brook. L. Rev.  (forthcoming 2024) (manuscript at 20–23); Natasha Brunstein, Taking Stock of West Virginia on its One-Year Anniversary, Yale J. on Regul.: Notice & Comment (June 18, 2023), https://perma.cc/TP5Y-HQGR; Ronald M. Levin, The Major Questions Doctrine: Unfounded, Unbounded, and Confounded, 112 Cal. L. Rev.  (forthcoming 2024) (manuscript at 31). Perhaps the Court will be a bit bolder, if it is inclined to predict opposition, adopting an across-the-board posture of Skidmore respect. Probably categorically off the table, in light of prevailing conditions of political uncertainty, is a more unequivocal move to an undiluted strategy of unconditional Chevron or across-the-board de novo review.

Conclusion

The very name of this symposium—”Chevron on Trial”—suggests finality. I hope to have convinced you, though, that this moment is hardly so determinative. Anybody hoping that Loper Bright and Relentless might bring an end to the need for symposia and Articles like this one is bound to be disappointed. Anybody who is fascinated by questions of where legal doctrines come from and what sustains them should pay attention. This moment is indeed historic and important, but it really just starts a new chapter.