TWO WEEKS before America’s Supreme Court considers whether Donald Trump may constitutionally remain on the presidential ballot, it will tackle a question closely tied to Mr Trump’s deregulatory plans for a second term. The power of some 436 federal agencies that do the bulk of the work of the federal government—from food safety to banking rules to pollution control—comes under the justices’ scrutiny on January 17th.

Herring—a silvery fish of the North Atlantic that can be smoked, pickled or, when young, tinned—is the unlikely star of Loper Bright Enterprises v Raimondo and Relentless v Department of Commerce. Both cases involve herring fishermen upset with the National Marine Fisheries Service (NMFS), a federal agency charged with safeguarding America’s ocean resources and habitat.

Drawing on a line in a statute giving the agency licence to make regulations that are “necessary and appropriate…to prevent overfishing and rebuild overfished stocks”, in 2020 the NMFS required fishermen to bring an observer along with them on their boats—and to pay that person’s per-diem fee themselves. Space on these vessels is a “scarce and precious resource”, the fisheries’ lawyer argues, making the NMFS’s rule (which was suspended in April 2023) an “enormous imposition”. Making the fishermen foot the bill “adds insult to injury”.

The rule nevertheless found receptive audiences at two of America’s appellate courts. In allowing the agency to impose the regulation, three-judge panels on both courts turned to a Supreme Court decision, Chevron USA v Natural Resources Defence Council, that has managed the inter-branch balance of power since 1984.

Chevron has two steps. First, judges determine if a law governing an administrative agency speaks clearly. If it does, judges interpret it themselves and tell the agencies what the law means. But if judges believe the law is ambiguous, they give bureaucrats the benefit of the doubt. At this second step, if the court sees the agency’s interpretation as reasonable—even if it is not the interpretation the court thinks best—it defers to the agency. In Loper Bright and Relentless, the circuit courts concluded that the law in question is ambiguous and that the NMFS’s interpretation of it is reasonable.

Chevron was popular among conservative justices in its early days. Five years after it was decided, Antonin Scalia (an arch-conservative justice who died in 2016) gave a lecture at Duke Law School in which he predicted that agency deference would endure as it “reflects the reality of government” and “serves its needs”. Yet two justices on the court today—Neil Gorsuch and Clarence Thomas—have made clear their deep disdain for what has become known as “Chevron deference”.

In a 2015 case involving the Environmental Protection Agency, Justice Thomas wrote that the wide berth Chevron afforded bureaucrats meant the court was “blithely giving the force of law” to “agency ‘interpretations’ of federal statutes” (note the scare quotes) and thereby straying “further and further from the constitution”. For Justice Gorsuch, who was railing against Chevron when he was still a judge on the 10th circuit court of appeals, agency deference is akin to “judicial abdication”.

The plaintiffs in Loper Bright and Relentless are banking on at least three more justices keen on reining in the administrative state. It may be a good bet. Brett Kavanaugh, two years before he became a justice, raised critical questions about Chevron in an article in the Harvard Law Review. The conservative majority has not invoked Chevron since 2016. The plaintiffs write that the doctrine has been “the-case-which-must-not-be-named” at the high court for years; the conservative court may see this as the moment to give Chevron, as Justice Gorsuch put it in 2022, “a tombstone no one can miss”.

Dozens of friend-of-the-court briefs urge the justices to do just that: bury-Chevron filings outnumber save-Chevron briefs by a ratio of four to one. But the implications of ditching the 40-year-old precedent are contested. For the plaintiffs, “Chevron’s primary victim is the citizenry” because the approach “literally gives the tie to their regulators in every close case”.

Not all regulations, though, are as hard to swallow as forcing fishermen to dole out up to a fifth of their profits to an on-board observer. Federal agencies, staffed by some 2.2m civil servants with expertise that judges often lack, protect workplace safety and respond to natural disasters. They keep aeroplanes and financial markets aloft. The government warns that abandoning Chevron—which lower courts continue to rely on even as the Supreme Court has quietly ignored it—would “threaten settled expectations in virtually every area of conduct regulated by federal law”. ■

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