A federal judge in Texas has ruled that the Biden administration's 2022 regulation on self-assembled firearms violates both the Second Amendment and the Due Process Clause, a decision gun rights groups are calling a vindication of a centuries-old American tradition.

U.S. District Judge Reed O'Connor, a George W. Bush appointee, sided with challengers who argued that the Bureau of Alcohol, Tobacco, Firearms and Explosives overstepped its authority when it required serial numbers on commercial firearms parts kits and mandated background checks for their buyers. The rule, adopted in 2022, attempted to clarify the definition of "frame or receiver" under the Gun Control Act of 1968 and treat self-assembled guns the same as any commercially manufactured firearm.

O'Connor found that the ATF's regulation ran headlong into the nation's historical tradition of personal gunsmithing and self-manufacture of firearms. He also determined the rule was so poorly written that it violated the constitutional guarantee of due process, the basic requirement that citizens be able to understand what the law demands of them before the government punishes them for breaking it.

The Hill reported that O'Connor wrote in his ruling:

"The Court cannot conclude that the Final Rule's imposition of ambiguous and far-reaching regulations, which would restrict access to component parts thereby inhibiting home gunsmithing, comports with the Second Amendment."

The Justice Department said it is "evaluating the impact of the court's ruling" but offered no indication of whether it plans to appeal.

O'Connor's ruling picks up where the Supreme Court left off

The decision lands months after the Supreme Court upheld the same ATF regulation in a 7-2 ruling. But that earlier decision was narrowly drawn. The justices addressed only whether the ATF had statutory authority under existing federal firearms law to issue the rule. They did not reach the constitutional questions, whether the rule violated the Second Amendment or was unconstitutionally vague.

Justice Neil Gorsuch, writing for the majority in that case, all but flagged the opening O'Connor walked through:

"Future cases may present other and more difficult questions about ATF's regulations. But we take cases as they come and today resolve only the question posed to us."

Two gun rights groups, including the Second Amendment Foundation, had pressed their challenge after the Supreme Court's decision, arguing that the constitutional issues the justices sidestepped still needed resolution. O'Connor agreed, and resolved them in the challengers' favor.

The ruling arrives as federal courts continue to shape the boundaries of Second Amendment law. The Supreme Court has agreed to hear a challenge to AR-15 bans, a case that could further define how far the government can go in restricting firearms Americans have long been permitted to own.

Gun rights groups say the rule was designed to chill lawful conduct

Adam Kraut, executive director of the Second Amendment Foundation, framed the ruling as a rebuke of bureaucratic overreach that left ordinary gun owners unable to figure out what was legal and what was not.

"The Court rightly held that the Biden ATF's rule not only sought to outright prohibit Second Amendment protected conduct but was written in such a vague and vaporous manner as to chill that protected conduct by making it impossible to even know what was legal and what wasn't."

That vagueness argument is worth pausing on. The ATF rule attempted to redefine what counts as a firearm "frame or receiver", the regulated core component of a gun. Critics argued the new definitions were so broad and ambiguous that hobbyists who have legally built firearms at home for generations could not tell whether their conduct now required federal licensing, serial numbers, or dealer involvement. O'Connor found those concerns well-founded and ruled the vagueness violated the Due Process Clause.

Americans have built their own firearms since before the founding. The practice is older than the ATF, older than the Gun Control Act, and older than the republic itself. O'Connor's ruling rested in part on that unbroken tradition, finding that the ATF's attempt to regulate homemade firearms parts out of practical existence conflicted with the Second Amendment's historical roots.

Gun control advocates warn of untraceable weapons

Not everyone welcomed the decision. Emma Brown, executive director of Giffords, a gun violence prevention advocacy organization, argued the ruling would open a dangerous gap in the background check system.

"Under the logic of this injunction, people ineligible to possess guns could get an untraceable ghost gun without any background checks or training. No one wants to live in a country where gun violence is easy to commit and almost impossible for police to solve."

Brown's argument assumes that the ATF rule was the only barrier standing between prohibited persons and firearms. But federal law already bars felons and other prohibited individuals from possessing any firearm, regardless of whether it carries a serial number. The question O'Connor addressed was whether the ATF could constitutionally impose sweeping new requirements on parts and kits, requirements that also burdened law-abiding citizens engaged in a practice the Constitution protects.

The broader pattern of federal courts drawing lines around executive-branch rulemaking continues across multiple policy areas. A federal judge recently cleared the Trump administration to end TPS protections for certain immigrant groups, another instance of the judiciary weighing in on how far agency authority extends.

Several key questions remain unanswered

O'Connor's ruling leaves significant loose ends. The scope of the decision is unclear, whether it applies nationwide or only within the judge's jurisdiction is not specified in available reporting. The precise remedy, permanent injunction, preliminary injunction, or another form of relief, is also uncertain, though Brown's statement references an "injunction."

The Justice Department's terse statement that it is "evaluating" the ruling offers no timeline and no commitment either way on an appeal. If the government does appeal, the case could land before the Fifth Circuit Court of Appeals and potentially return to the Supreme Court, this time with the constitutional questions front and center.

Meanwhile, courts across the country are grappling with the limits of federal authority on issues ranging from firearms to immigration. A Hawaii Supreme Court justice recently declared that his state would chart its own path on constitutional interpretation, a sign of the growing tension between state and federal judicial authority.

And in Congress, lawmakers continue to push policy initiatives that test constitutional boundaries. Sen. Jim Banks has revived the birthright citizenship debate with new legislation, another front in the ongoing contest between elected officials, executive agencies, and the courts over who gets to set the rules.

The Biden administration's ghost gun rule was sold as a common-sense measure to close a regulatory loophole. O'Connor's ruling says it was something else: a vague, far-reaching regulation that restricted constitutionally protected conduct without historical precedent. Whether the government fights to save it or lets it fall will say a great deal about how seriously Washington takes the constitutional limits it so often claims to respect.

When an agency writes a rule so broad that citizens cannot tell what it forbids, and so untethered from history that a federal judge calls it unconstitutional on two separate grounds, the problem was never the gun owners. It was the rule.