The most important and frequently cited case in administrative law is Chevron v. NRDC—a case mandating judicial deference to legal interpretations by administrative agencies. This year the Court is likely either to overrule it directly or hollow it out significantly. The rise and fall of Chevron is a fascinating story both jurisprudentially and for me personally. As an intern in the Solicitor General’s office who worked on the Supreme Court brief for the government, I was present at its creation. Neither I nor, I believe, anyone else in the office had the slightest inkling that this case would have importance outside of the Clean Air Act, the statute that it concerned. It is often said that hard cases make bad law, but Chevron shows that obscure and seemingly unimportant cases can make epochal law.

Chevron is of even more enduring interest for what it says about the power of high-level jurisprudential concerns to shape concrete legal doctrine. Chevron’s language mandating deference to administrative agencies appeared and then became popular because judicial activism was the overriding concern of its era. After the excesses of the Warren Court, there was a widely shared fear that courts were substituting their own views for the law. At the Supreme Court level, the Warren Court was often thought to substitute its views of good policy for the law. In administrative law, however, the most frequent offender was thought to be the era’s District of Columbia Circuit which substituted its view of good policy and procedure for those of relevant federal agencies. Deference became the answer to administrative judicial activism. It was not coincidental that in Chevron, the Supreme Court overturned a DC Circuit decision below.

But over time jurisprudence itself changed. More judges became textualists in statutory interpretation and originalists in constitutional law. Formal analysis rather than policy became the exclusive stuff of law. If courts confine themselves to formalism, there is no reason to defer to agencies. Judges are the experts in squeezing statutes until they squeal their meaning. They are less biased when engaged in this formal enterprise than more politically beholden agencies with skin in the game.

Thus, while some commentators, like Harvard Professor Noah Feldman, have presented the likely overruling of Chevron as a malign attempt by the right to curb the administrative state while others have seen it as an ideological effort to empower the conservatism of a largely Republican-appointed judiciary, these charges are simplistic and does not accord with history. The right has long had doubts about the power and accountability of the administrative state. The courts have often had a majority of Republican-appointed justices and judges since Chevron was decided. What is new since 1984 is the rise of formalism and the confidence that formalism can deliver correct answers to complex questions of statutory interpretation. Moreover, overruling Chevron does not change the delegation doctrine, which remains the engine of the administrative state. Even if Chevron is overruled, Congress can still delegate ample discretion to administrative agencies. It is just that agencies will no longer get deference in interpreting what that discretion is.

Chevron at the Beginning

In the summer of 1983, Harvard Law Professor Paul Bator, from whom I had taken administrative law, invited me to become a summer intern in the Office of the Solicitor General, the Supreme Court litigating arm of the Department of Justice. One of the first cases I worked with him on was Chevron. Under the Clean Air Act, a new “source” of pollution triggered a requirement that a company use the best available technology on any machines from which the pollution emanated. The EPA administrator in the Reagan administration (who was, incidentally, Ann Gorsuch, the mother of Neil Gorsuch) issued a regulation to allow states, which had responsibility for enforcing these requirements, to treat “new source” to encompass an entire plant. That position meant that plants could efficiently reduce pollution from one machine in the plant and put in another; so long as the change did not result in more pollution from the plant overall, it would not trigger the expensive requirement of using the best available pollution-reduction technology. Environmental groups sued to reject this “bubble” concept. They wanted the best technology requirement to be triggered by any new production unit within a plant that emitted pollution.

Professor Bator decided to pitch the government’s argument on the notion that the statute did not provide an answer to the question of what size unit was a source. Since the EPA had clear statutorily delegated authority to make rules to carry out the act, it could fill in the gaps and interstices of the statute. While our brief did briefly cite a previous case that had boilerplate language about providing deference to agency regulation, deference was not our key argument. Nor did Professor Bator even mention the word in his oral argument. Instead, he emphasized, the EPA was acting under the broad discretion that Congress gave it.

The Rise of Chevron Deference

In the Chevron decision, Justice John Paul Stephens, however, made the case all about deference, suggesting that the judiciary should defer to the interpretation of a statute unless Congress had “directly spoken to the issue.” If the intent were clear, the Court was justified in invalidating the agency’s action or regulation. That was Chevron Step One. But otherwise, it should uphold the agency, so long as its action or regulation was “reasonable.” That was Chevron Step Two. The Court justified its position on accountability grounds—agencies are accountable to the President and he in turn is more accountable to the people (and to Congress) than are the courts.

Jurisprudentially, the analysis of the Chevron opinion looks two ways. On the one hand, it actively enforces a regime of deference: Unless Congress has a specific and clear intent on the matter, courts are to defer to the agency. In the zeitgeist of the time, that was the response to the reality of judicial activism. But on the other hand, it also accepted to some degree that the stuff of law was policymaking. For instance, in Chevron Step Two, the courts were to assess whether the agency’s action or regulation was a “reasonable interpretation.” Scholars have had trouble distinguishing what a court is to do in Step Two from “arbitrary and capricious” review under the Administrative Procedure Act, which explicitly mandates courts to assess the rationality of the agency’s policy calculus. If policy was a central consideration in determining how to interpret a statute, it followed that agencies were in a better position to make that determination in most circumstances. Moreover, any policy calculus inevitably turned on the weight of several factors that went into it. There would be no one right answer, and different administrations could strike the balance in accordance with their own weighting.

The government, of course, began to seize on Chevron to defend its regulations, and it became widely cited for two reasons. First, it offered a two-part test that simplified the busy work of courts of appeals by permitting them to punt to agencies. Second, it accorded with the jurisprudential world of the time—one where activism had become a concern but where textualism—in my view better known as statutory originalism—had not become the formidable force that it is today. As a result, Chevron rapidly became the most cited case in administrative law. The Court modified and adjusted the Chevron doctrine, but its continuing power three decades later was demonstrated in the Brand X decision, which held that even if a court has interpreted a statute to mean something, an agency did not have to follow that interpretation in a subsequent regulation unless the interpretation were of a specific and clear congressional intent. Agencies continued to have a lot of running room for their own interpretations.

The Fall of Chevron Deference

But jurisprudential times changed. The memories of constitutional judicial activism on the Supreme Court and administrative judicial activism on the DC Circuit faded. The primary concern that had motivated Chevron’s doctrine of deference was no longer as salient. More importantly, the way of interpreting texts changed from considering policy or purpose to formal parsing of language. Thus, even when Congress has no specific intent on a question, the text could still answer that question, particularly when aided by the traditional canons of statutory interpretation. Judges, not agencies, were the experts in deploying traditional statutory methods. Furthermore, many came to believe that this kind of formalism can yield a right answer. When they deferred to agencies (which were policy experts, but not legal ones), judges were abnegating their duty to say what the law was.

Judges began to seize on a neglected footnote in Chevron, suggesting that courts should deploy these canons of interpretation before deferring. That footnote was somewhat at odds with Chevron’s mandate in its text to defer unless there was a specific intent. After all, many of these canons come into play at times of ambiguity, precisely when there is no clear intent. But nevertheless, textualists used that footnote to reduce the force of Chevron.

And because of its own turn to right-answer formalism, the Supreme Court itself has not cited Chevron to defer to an agency since 2016. But lower courts often still rely on it. Chevron provides a framework for quick decisions and helps cut down on the time needed to do the challenging work of formal statutory interpretation. And some judges, particularly those appointed by Democratic presidents, do not agree with the formalist revolution in law.

When the Court overrules or radically reduces the scope of Chevron, it will be marching to a jurisprudential tune, not an ideological beat. Just as ages have their distinctive philosophies and economic perspectives, so they have their jurisprudential outlooks. Look at opinions of the Supreme Court through the decades. Their era can be identified not only by the issues they address and the decisions they hand down, but by their distinctive methodologies. And that high-level jurisprudence sometimes reaches down and decides concrete cases. Such was the case with Chevron and so it will be with the case that tolls its demise.