The Supreme Court on Tuesday allowed the Biden administration to temporarily reinstate a rule by the Bureau of Alcohol, Tobacco, Firearms, and Explosives regulating “ghost guns” while a challenge to the rule continues in a federal appeals court. In June, a federal judge in Fort Worth, Texas, had barred the ATF from enforcing the rule anywhere in the United States. Urging the justices to intervene, U.S. Solicitor General Elizabeth Prelogar had told the justices that the order by U.S. District Judge Reed O’Connor was “irreparably harming the public and the government by reopening the floodgates to the tide of untraceable ghost guns flowing into our Nation’s communities.”

The vote was 5-4, with Justices Clarence Thomas, Samuel Alito, Neil Gorsuch, and Brett Kavanaugh indicating that they would have denied the government’s request and allowed the ban on enforcement of the rule to continue. The ATF issued the rule at the center of the dispute in 2022 to make clear that federal laws governing the sale of firearms – requiring, for example, background checks for purchases and imposing recordkeeping obligations – apply to “ghost guns,” firearms without serial numbers that virtually anyone can assemble with parts that they purchase, often in a kit.

Manufacturers and sellers of ghost gun kits and parts went to court to challenge the rule, arguing that its application to ghost guns was inconsistent with federal firearms laws. On June 30, O’Connor vacated the rule nationwide. The 5th Circuit agreed to fast-track the government’s appeal but rejected the government’s plea to put O’Connor’s ruling on hold, although it did limit his ruling to the parts of the rule that the manufacturers and sellers had specifically challenged. Oral argument in the 5th Circuit is scheduled for Sept. 7.