The Supreme Court reinstated for a second time the Biden administration’s regulations on “ghost guns” — unassembled, unmarked gun kits that can be purchased online. In 2022, the federal government imposed similar regulations on the DIY guns to standard guns, including mandating serial numbers and background checks for purchasers. A federal judge in Texas issued a nationwide injunction on the Biden rule, but Tuesday’s Supreme Court ruling will allow the regulations to stand while a legal challenge plays out.