There’s a new contender for what the next big Supreme Court gun case could be.

On Friday, the Fifth Circuit Court of Appeals voted 13-3 to strike down the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) Trump-era ban on bump stocks. In its ruling, the majority said that the ban violated the Administrative Procedure Act when it attempted to interpret the devices as falling under the federal definition of “machinegun.”

“A plain reading of the statutory language, paired with close consideration of the mechanics of a semi-automatic firearm, reveals that a bump stock is excluded from the technical definition of ‘machinegun’ set forth in the Gun Control Act and National Firearms Act,” Judge Jennifer Walker Elrod wrote for the majority.

The ruling now creates what’s known as a “circuit split,” in which multiple federal courts of appeals have come down on opposite sides of an issue. Before Friday’s decision, the Tenth Circuit in 2020, the Sixth Circuit in 2021, and the D.C. Circuit in August 2022 all ruled to uphold the ATF’s interpretation of bump stocks as machineguns. A three-judge panel for the Fifth Circuit, comprised of judges all appointed by Democratic Presidents, also previously ruled to uphold the ban. 

Circuit splits are often, though not always, a precondition for the Supreme Court when deciding which cases to grant certiorari. That’s because it’s the High Court’s prerogative to ensure a unified interpretation of the law that lower courts follow. Should the Biden administration appeal the Fifth Circuit’s decision to the High Court, the likelihood that the nine justices will agree to review the case has increased considerably.

This is significant for several reasons. Not least of which is that, until this point, the Court has publicly shied away from hearing challenges to the ban. Three prior attempts to have the court review separate cases involving the ban were all rejected without comment from the justices. That left gun owners forced to surrender their lawfully purchased property uncompensated and without immediate recourse. It also left those who refused to comply with the ban at further risk of a federal felony offense. The new circuit split gives those gun owners another chance to beat the ban.

The Court taking the bump stock case would provide further reason to think it plans to more aggressively pursue gun-related cases, even if they don’t directly hinge on Second Amendment jurisprudence. Rather than relying on the Court’s new standard of review for gun cases, the Fifth Circuit ruling hinged on limits surrounding an executive agency’s power to interpret federal law. That has been a longstanding bugaboo for many of the Court’s conservative majority, and they’ve already shown a willingness to rein in regulatory bodies acting beyond their statutory authority as recently as the last court session.

Should SCOTUS decide to weigh in once again on the limits of administrative rulemaking, it could also affect the legality of the ATF rules stemming from President Joe Biden’s executive orders. At least two separate lawsuits have already been filed against the ATF’s newest rule on so-called ghost gun kits and unfinished firearm parts. The agency has shown a similar willingness to shift the goalposts on how aggressively it will interpret that rule against gun dealers.

Furthermore, the agency’s final rule on stabilizing pistol braces is expected to be released this month. It’s even more similar to the Trump-era bump stock ban. The aggressive interpretation of pistol braces as National Firearms Act-regulated items the ATF is pursuing would turn millions of Americans into federal felons for owning something they lawfully purchased and which they were previously assured was a legal item by the ATF.

The Fifth Circuit ruling against the bump stock ban already represents a substantial legal roadblock for the Biden-era rules. And, should it decide to weigh in, the Supreme Court’s decision on bump stocks would foreshadow the legality of ATF’s most recent two rules.

Much will depend on the next steps taken in the Cargill case. The Fifth Circuit’s ruling will likely be appealed. It’s hard to imagine the Biden administration allowing bump stocks to become legal in Texas, Mississippi, and Louisiana.

Gun-rights advocates who’ve fought the ban since 2018 have plenty of incentive to bring a case to the High Court through one of the other circuits if Biden decides to do nothing.

If a bump stock case makes it to the Supreme Court, the chances are higher than ever that the justices will take it up. The outcome of such a case would have a massive impact on the future of executive branch gun-control efforts just as they’re becoming a common bi-partisan workaround to the legislative process.