On June 28, the Supreme Court’s conservative majority struck down a four-decade-old legal precedent known as Chevron deference, which allowed federal agencies to broadly interpret federal law. 

The ruling could have ramifications for the Bureau of Alcohol, Tobacco, Firearms and Explosives, the federal agency in charge of regulating firearms, legal experts tell The Trace. 

“The opinion will affect gun regulations like it’ll affect all agency regulations, and perhaps more,” said Eric Ruben, an assistant law professor at Southern Methodist University. “The courts are especially divided on gun law questions right now, and there are some that will be inclined to construe federal laws that delegate authority to the ATF narrowly.”

Chevron held that the courts should defer to federal agencies to interpret ambiguous federal laws. Now it will be up to the courts, as opposed to experts and scientists who work for the government, to decide whether federal laws are in line with Congress’s intent.

The 6-3 ruling in Loper Bright Enterprises v. Raimondo gives the courts unprecedented veto power over federal regulation, and could also dilute the authority of other agencies like the Food and Drug Administration, Environmental Protection Agency, Consumer Financial Protection Bureau, Consumer Product Safety Commission, and Department of Labor. 

The ATF issues rules in response to advancements in firearms technology, as it’s done in recent years with bump stocks, ghost gun kits, and pistol braces. Now it would be up to the courts, whose judges are not necessarily firearms experts, to interpret federal statutes. 

Congress can pass legislation directly addressing these areas of law, something the court’s conservative justices suggested when it struck down the ATF’s bump stock rule earlier this month. But Congress is slow to action and hampered by political polarization.

“The court wants Congress to take the leading role in regulating the nation,” said Adam Winkler, a law professor at the University of California, Los Angeles. “But one has to wonder if it’s a misplaced faith. Congress seems structurally unable to tackle any of the major problems facing the country right now.”

The Loper Bright ruling could effectively paralyze the ATF’s rulemaking authority by exposing a wide array of rules and regulations to court challenges. “One thing overturning Chevron does is encourage litigation,” Winkler said. “It’s going to open the floodgates for any regulation to be challenged. So litigants will be incentivized to bring cases because there’s now a greater chance that they’ll win.”

This could have a chilling effect on the ATF, which might think twice before issuing a rule that will be tied up in court for years and ultimately tossed. “Just the fact that you’re going to have to deal with those lawsuits may make regulators more reluctant to adopt regulations,” Winkler said. And federal regulators will now have to consider the chance that a rule will be overturned when calculating its odds of success.

SCOTUS had an opportunity to address Chevron in its recent decision overturning bump stocks, but sidestepped it. In Garland v. Cargill, the court’s conservative justices ruled that the definition of “machine gun” in federal law does not apply to bump stocks, and as a result, the ATF exceeded its authority in regulating them. There the statute was clear, not ambiguous, so the ATF was not afforded the Chevron deference.

Winkler, the UCLA professor, said that the overturning of Chevron might find courts deferring to some federal agencies more than others. But “one might imagine that the Supreme Court would be less deferential to gun regulators because of the court’s support of the Second Amendment,” he said, citing the recent bump stock decision.

For all the hurdles that the overturning of Chevron will create for the ATF, “there’s not a lot of very significant regulations that can be adopted by ATF when it comes to regulating guns,” Winkler said. That’s because pro-gun lobbyists had a hand in writing gun laws that include restricting the ATF’s authority. “Even if you just make it harder for those agencies to act, their field of action is already very small.”

Chevron has been used to uphold facets of some of America’s foundational gun laws, including the FBI’s authority to temporarily retain background check records for auditing purposes, and a prohibition on undocumented residents possessing firearms. According to Chief Justice John Roberts, who wrote the majority opinion, the Loper Bright ruling is not retroactive, so any regulations that relied on Chevron would be unaffected — though Justice Elena Kagan wrote in her dissent that “some agency interpretations never challenged under Chevron now will be.”

The opinion will affect gun regulations like it’ll affect all agency regulations, and perhaps more.

Eric Ruben, assistant law professor at Southern Methodist University

The overturning of Chevron was immediately cheered by conservatives, who have been aiming to gut federal authority for decades, specifically in the area of environmental regulation. Gun rights groups also welcomed the decision. “For 40 years, the Chevron precedent allowed ATF and other executive agencies to run amok and interpret the law arbitrarily to the detriment of our natural rights,” the Firearms Policy Coalition posted on X, the social media platform formerly known as Twitter. 

In amicus briefs submitted to the Supreme Court, the Firearms Policy Coalition, the National Shooting Sports Foundation, and Gun Owners of America argued that the ATF has used Chevron to essentially rewrite federal gun regulations, pointing to the bump stock rule, a rule that updated the ATF’s definition of a firearm to allow it to regulate ghost guns, and a rule governing pistol-stabilizing braces. 

Gun Owners of America claimed in a post on X that “judges used Chevron against the Second Amendment” by consistently siding with the ATF that its statutes were “reasonable.” “Thank GOODNESS the absurdity of Chevron is over,” the group wrote.

The Supreme Court’s liberal minority argued that federal agencies have more expertise than the courts and they’re best equipped to interpret federal laws. “Congress knows that it does not — in fact cannot — write perfectly complete regulatory statutes,” Justice Kagan wrote in her dissent, which she read aloud from the bench. “It knows that those statutes will inevitably contain ambiguities that some other actor will have to resolve.” Some of those ambiguities “involve scientific or technical subject matter. Agencies have expertise in those areas; courts do not.”