The Supreme Court has declined to reinstate a Missouri law that prohibits local police from collaborating with federal authorities to enforce certain gun laws. In a victory for the Biden administration, the justices denied Missouri's emergency application to put the law back into effect while a legal challenge proceeds in a lower court, as reported by The Hill.

Justice Clarence Thomas publicly dissented, expressing his disagreement with the majority decision. However, two conservative justices who voted against Missouri's request suggested that private parties could still enforce the law.

Missouri's Second Amendment Preservation Act, passed in June 2021, argues that restrictions on gun transfers and firearm registrations are unconstitutional. According to the law, police and other state and local government employees are prohibited from enforcing provisions deemed invalid, with violators facing civil fines of up to $50,000.

The Biden administration had previously filed a lawsuit against Missouri's law, asserting its unconstitutionality. In March, a federal district judge concurred with the administration's stance. Despite the ruling, the law remained in effect until recently when the 8th U.S. Circuit Court of Appeals denied Missouri's request for a stay as they proceed with their appeal.

In an attempt to revive the law, Missouri turned to the Supreme Court, arguing for its constitutionality and claiming that the Biden administration lacked the standing to sue. Justice Neil Gorsuch, along with Justice Samuel Alito, implied that private parties could still enforce the law, highlighting the limitations of the district court's order.

Missouri contended that the lack of explanation provided by the 8th Circuit constituted irreparable harm to the state if the law continued to remain off the books.

The Biden administration, on the other hand, urged the Supreme Court to stay out of the case, maintaining that the law was unconstitutional for various reasons. They argued that Missouri's attempt to nullify federal statutes and regulate federal officials enforcing those statutes was not within their purview.

The case may potentially return to the Supreme Court on the merits at a later date. As it stands, the Supreme Court's decision to deny reinstating the Missouri gun law aligns with the Biden administration's position.