California Court Blocks State Mandate to Show Id on Federal Officers A federal appeals court has ruled that California cannot force federal immigration agents and other federal officers to display identification during enforcement operations, citing the Supremacy Clause. The decision revokes a state law's requirement for federal agents to show agency names or badge numbers, reversing a lower court ruling and imposing a preliminary injunction against the new law. The ruling came after California's No Vigilantes Act, enacted in 2025, sought to regulate federal conduct in immigration sweeps. A California federal appeals court has ruled that the state cannot compel federal immigration agents and other federal officers to display identification during enforcement operations. The court found that Section 10 of California's "No Vigilantes Act" violates the Supremacy Clause of the U.S. Constitution. The decision overturns a lower court ruling and grants a preliminary injunction preventing the state from enforcing the identification requirement against federal agencies and officers. Section 10 of the No Vigilantes Act required non‑uniformed law‑enforcement officers working in California, including federal agents, to visibly display their agency name or badge number while carrying out enforcement duties.Supremacy Clause Violates State Identification RulesOfficers who refused to comply risked misdemeanor prosecution by the state. In writing for the three‑judge panel, Chief Judge Mark Bennett explained that the measure effectively attempts to directly regulate a federal agency as it performs its legitimate functions."The state cannot stand on the shoulders of the federal government and dictate how it exercises core government functions, unless Congress explicitly authorizes such interference," Bennett said. Because law enforcement is a fundamental government activity, the court held that the identification mandate is invalid for every application to federal officers acting under federal authority.The panel asserted that the federal government was "certain" to prevail on its constitutional challenge, rejecting the argument that the law did not substantially interfere with federal operations. The No Vigilantes Act was enacted in 2025 following a series of federal immigration sweeps across California. During those sweeps, masked agents in unmarked vehicles conducted arrests and detentions, drawing criticism from Democratic officials and raising concerns about due process and the doctrine of political neutrality.Governor Newsom Law Blocked by Appeals CourtGovernor Gavin Newsom signed the act into law, which was later complemented by the No Secret Police Act that restricts officers from wearing face coverings. The latter was blocked by a district judge earlier this year. With the appeals court siding with the Trump administration, California's options for enforcing the identification requirement are now severely limited.The three‑judge panel-comprising Obama appointee Jacqueline Nguyen and Trump appointees Mark Bennett and Daniel Collins-carefully differentiated between the valid state authority to regulate private and local entities and the unconstitutional attempt to control federal conduct. The court noted that while the state has legitimate interests in ensuring transparency and accountability for officers exercising authority in public spaces, those interests cannot override the federal government's autonomy under the Constitution.Federal immigration agents may continue to operate in California without the requirement to display identifying information or other similar mandates from state law. The ruling also underscores the enduring principle that states cannot impose regulations on federal officers unless the federal legislature gives permission. The decision is likely to resonate beyond California, informing ongoing debates over the extent to which states can regulate the conduct of federal law‑enforcement agencies.Federal Ruling Sets National Precedent for StatesThe ruling was published on June 15, 2024, and is expected to set a precedent for other states that have attempted to regulate federal officers in the wake of national security concerns and border enforcement initiatives. The court emphasized that future conflicts between state and federal law over jurisdiction must resolve consistent with the Supremacy Clause, which ensures that federal law remains the supreme law of the land.California will now need to adjust its enforcement strategy to align with federal guidelines while still pursuing its objectives of transparency and accountability among all law‑enforcement actors operating within the state.