This opinion piece was first published by The Wall Street Journal.

Conservatives often criticize liberal jurists for “judicial activism”—disregarding laws passed by elected legislators and imposing their own policy preferences instead. On Wednesday the Supreme Court will consider whether to overturn a precedent that went too far in the other direction by surrendering the judicial role of interpreting the law and handing it to unelected bureaucrats and agency heads.

Loper Bright Enterprises v. Raimondo is a case about fishing regulation. The National Marine Fisheries Service issued a rule requiring the plaintiffs to pay the costs of carrying federal conservation monitors aboard their vessels. The fishermen argued that the service had no legal authority to do so, but the high court’s precedent in Chevron v. NRDC (1984) obligated the U.S. Circuit Court of Appeals for the District of Columbia to defer to the government’s interpretation of an “ambiguous” statute.

Chevron was an “accidental landmark,” as legal scholar Thomas Merrill put it in 2014. At issue in the case was a Clean Air Act regulation interpreting the term “stationary source” to refer to an entire facility rather than a single smokestack. This definition enabled facilities to make changes that didn’t increase their total pollution without triggering onerous permitting requirements for “new or modified” sources. The justices upheld the regulation, deferring to the agency’s interpretation of “ambiguous” text.

For as long as they’d had the power to do so, federal courts interpreted statutes for themselves where necessary to decide a case, including in cases challenging agencies’ positions on the laws they administer. Chevron superseded that approach with a blanket rule of deference.

It’s unclear if the high court intended this fundamental change. Chevron’s author, Justice John Paul Stevens, regarded the decision as ordinary pragmatism: “When I am so confused, I go with the agency,” he told his colleagues as they discussed the case in conference.

By all indications, Chevron’s reasoning was driven by the need to assemble a court majority on a difficult interpretive question. That explains the decision’s failure to grapple with the obvious consequences of its logic. The Constitution vests the “judicial power” in the courts. “It is emphatically the province and duty of the judicial department to say what the law is,” as Chief Justice John Marshall wrote in Marbury v. Madison (1803). Chevron bucked that constitutional command without acknowledging that it did so.

Chevron deference also conflicts with the Administrative Procedure Act of 1946, which provides that a “reviewing court shall decide all relevant questions of law” and “interpret constitutional and statutory provisions.” Chevron doesn’t cite the APA.

While few appreciated Chevron’s import when it was handed down, its potential was apparent to the Justice Department. The Reagan administration seized on the decision as a corrective to the judicial activism of lower courts, especially the D.C. Circuit, in blocking its deregulatory agenda. The Chevron doctrine bulldozed the policy-driven obstacles courts had thrown up to block regulatory reforms. It gained adherents among newly appointed textualist judges like Antonin Scalia and Kenneth Starr on the D.C. Circuit, who favored judicial restraint.

But over the years Chevron became less about judicial restraint and more about agency dominance. With the movement toward textualism, led by Justices Scalia and Clarence Thomas, courts gradually returned to constrained formalism in interpreting statutes. Armed with the Chevron doctrine, however, the administrative state learned to wield its new interpretive power to maximum effect.

Deference might have been relatively harmless if agencies engaged in a good-faith effort to carry out unclear statutes. But beginning in the Clinton administration, Chevron changed the way they go about their business. Instead of asking what Congress meant, agency lawyers and decision makers hunt for ambiguities, real or imagined, to justify their policy objectives.

As agencies relied more on Chevron to pursue policy agendas, judges were forced to confront a greater range of asserted “ambiguities” with no standard to distinguish among them. Judicial review is the essential check on executive overreach, yet Chevron put a brick on the scale by committing the courts to favor the government’s positions. It is all too easy for courts, when faced with difficult or contentious interpretive questions, to waive the ambiguity flag and defer.

By aggrandizing the power of unelected bureaucrats, the Chevron doctrine also diminishes Congress. Witness the unseemly but now-routine spectacle of lawmakers hectoring the president and agencies to enact policy programs—from student-loan forgiveness to the expansion of antitrust law and greenhouse gas-regulation—rather than legislating themselves. The prospect of achieving an uncompromised policy win through executive action has replaced the give-and-take of the legislative process.

But the victories achieved in this fashion are only as durable as the current administration, and each new president takes office with a longer list of “day one” executive actions to reverse his predecessor and implement his own agenda. Donald Trump raised hackles last month when he said he would be a “dictator,” but only on “day one.” He was describing the post-Chevron presidency.

The principal argument of Chevron’s defenders is “reliance.” Ending deference to agencies, they say, would create regulatory uncertainty and threaten the viability of the administrative state. But what reliance interest can there be in a doctrine that empowers agencies to change course on a political whim, over and again?

The Supreme Court has already been moving away from Chevron deference, which it hasn’t applied since 2016. The Covid pandemic heightened the need for agency flexibility, yet none of the justices’ pandemic-policy decisions resorted to deference. In recent years, 13 states have rejected Chevron-style deference in interpreting state law without consequence.

Chevron’s rule of deference is an abdication of judicial duty, not an exercise in judicial restraint. It has proved unworkable and corrosive to the constitutional separation of powers. Forty years later, the court should correct its mistake.

Mr. Rivkin served at the Justice Department and the White House Counsel’s Office in the Reagan and George H.W. Bush administrations. Mr. Grossman is a senior legal fellow at the Buckeye Institute and an adjunct scholar at the Cato Institute. He filed a friend-of-the-court brief in support of the petitioners in Loper Bright. Both authors practice appellate and constitutional law in Washington.