A federal judge in Texas has declared that a regulation adopted by Democratic former President Joe Biden’s administration targeting largely untraceable “ghost guns” is unconstitutional — a ruling issued after the U.S. Supreme Court last year upheld the measure.

U.S. District Judge Reed O’Connor in Fort Worth ruled on Monday that the 2022 rule violates the right to keep and bear arms under the U.S. Constitution’s Second Amendment and was too vague to satisfy the Fifth Amendment’s due process guarantees.

The Supreme Court in March 2025 overturned an earlier ruling that O’Connor had made in the case that found the rule targeting parts and kits for ghost guns to be unlawful.

The Supreme Court’s 7-2 ruling focused not on whether the rule comported with the Constitution but instead on whether the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives had exceeded its authority in adopting it.

The regulation requires manufacturers of firearms kits and parts, such as partially complete frames or receivers, to mark their products with serial numbers, obtain licenses and conduct background checks on purchasers as already required for other commercially made firearms.

The rule also specified that the kits and components are covered by the definition of “firearm” under the 1968 Gun Control Act and that commercial manufacturers of such kits must become licensed.

Following the Supreme Court’s ruling, the gun rights group Second Amendment Foundation and a manufacturer of some of the targeted products, Defense Distributed, asked O’Connor to again block the rule’s enforcement on grounds that the Supreme Court did not address.

O’Connor, who was appointed by Republican former President George W. Bush, said the rule infringes on a person’s right to make or repair personal firearms by restricting access to necessary components and “contradicts the actual historical tradition of personal gunsmithing.”

“Self-manufacture of firearms in America was common and indeed foundational to establishing our Nation,” O’Connor wrote.

The judge blocked the rule from being enforced against Defense Distributed as well as the Second Amendment Foundation’s members with respect to some of the company’s products. The group’s executive director, Adam Kraut, hailed the ruling in a statement, calling the Biden-era rule “a mess.”

The U.S. Justice Department, which oversees ATF, did not immediately respond to a request for comment.

While the department under Republican President Donald Trump has been more supportive of expansive gun rights than the Biden administration, it had defended the “ghost guns” rule in court.

“There is no Second Amendment right to buy or sell an untraceable ghost gun kit without a background check. This decision is egregiously wrong, and we expect the Justice Department to promptly appeal,” Eric Tirschwell, executive director of the gun control advocacy group Everytown Law, said in a statement, referring to O’Connor’s ruling.

(Reporting by Nate Raymond in Boston; Editing by Will Dunham)