A federal appeals court sided with the Trump administration on Wednesday in its legal fight with California over immigration enforcement, holding that the state cannot make federal immigration agents display identification under a law aimed at plainclothes officers working in the state.
In a published opinion in United States v. State of California, a panel of the U.S. Court of Appeals for the 9th Circuit set aside a trial judge's denial of the preliminary injunction the federal government had sought and sent the case back with instructions to enter one. The injunction is to bar the state, its governor and its attorney general from applying or enforcing Section 10 of the No Vigilantes Act. Judge Mark J. Bennett wrote for the panel.
The panel held that the provision violates the Constitution's Supremacy Clause, which, the court said, "prohibits States from directly regulating federal operations even when regulating state operations in the same manner." "As before, we conclude ... the No Vigilantes Act attempts to directly regulate the United States in its performance of governmental functions," Bennett wrote. "No set of circumstances exist under which the Act would be valid."
U.S. District Judge Christina A. Snyder had blocked a companion law banning masks for law enforcement, because it exempted state peace officers, but she let the identification requirement stand, agreeing with the state that it worked more like a highway speed limit than a direct regulation of the federal government. The appeals court disagreed. A state law that directly regulates the federal government's conduct without congressional authorization, Bennett wrote, "is void irrespective of whether the regulated activities are essential to federal functions or operations, and irrespective of the degree to which the state law interferes with such functions or operations."
California passed the identification law in response to immigration raids across the state last year. The Justice Department sued the state and Gov. Gavin Newsom in November 2025 after the measure was signed; it requires plainclothes officers to "visibly display identification." The requirement took effect Jan. 1, but in April the 9th Circuit sided with the department and kept the law on hold until the case was resolved.
Wednesday's decision orders interim relief, not a final judgment. A preliminary injunction holds the law back while the litigation continues, and the case now returns to the trial court.
Bill Essayli, the first assistant U.S. attorney for the Central District of California, welcomed the ruling. "Huge win for the Supremacy Clause," he said. "California continues to violate the U.S. Constitution, and we will continue to hold them accountable."
Attorney General Rob Bonta's office did not immediately respond to a request for comment from The Hill. The office has argued that the law was needed to provide "transparency and accountability," and it has accused the administration of using federal law enforcement to step "well outside the boundaries of normal practice." Responding to earlier court setbacks for the state, a Newsom spokesperson said "these laws shouldn't even be necessary" and added: "We shouldn't have unidentified, masked men terrorizing our communities."
California is not alone. More than a dozen other states have pursued similar statutes, according to the Los Angeles Times. California lawmakers also enacted new laws this year that ban "wearable electroshock devices," bar ICE agents accused of serious misconduct from state employment and let residents sue ICE officials. Writing about the shock-device ban, staff of the state Senate Public Safety Committee warned that provisions "seeking to regulate federal agencies and their agents will undoubtedly be subject to legal challenge under the doctrines of intergovernmental immunity and conflict preemption."