On February 9, 2026, the United States District Court for the Central District of California denied the United States’ request for a preliminary injunction preventing California from enforcing Section 10 of the No Vigilantes Act (Senate Bill 805 or “the Act”), which required non-uniformed federal law enforcement officers operating in California, subject to certain narrow exceptions, to visibly display identification while performing federal law enforcement duties, and subjected violators to criminal prosecution by the state. The United States appealed this portion of the district court’s ruling, and on October 14, 2026, a three-judge panel of the Ninth Circuit reversed the district court’s ruling and remanded with instructions to enter a preliminary injunction against enforcement of Section 10 of the Act.
In order to obtain a preliminary injunction, the United States had to show that it was likely to prevail on the merits of its challenge to Section 10 of the Act, that it was likely to suffer irreparable harm in the absence of the relief requested, that the balance of the equities tipped in its favor, and that a preliminary injunction would be in the public interest. The Ninth Circuit determined that the United States satisfied all four factors, concluding that it was not merely likely, but “certain,” to succeed on the merits of its constitutional challenge.
The Ninth Circuit held that the United States showed that there was no set of circumstances under which Section 10 of the Act would be valid under the Supremacy Clause’s doctrine of intergovernmental immunity. That doctrine provides that states such as California are prohibited from directly regulating the operations or property of the federal government, unless Congress clearly and unambiguously authorizes such regulation. Absent clear and unambiguous congressional authorization, any state law that directly regulates the federal government’s conduct is void, regardless of whether the activities being regulated are essential to the federal government’s functions or operations and of the degree of interference. The Ninth Circuit reasoned that, without the required congressional authorization, Section 10 regulated the performance of quintessential government conduct, specifically law enforcement, carried on by the federal government by applying to federal law enforcement agencies and officers, and was therefore barred by the doctrine of intergovernmental immunity.
The Ninth Circuit rejected California’s argument that a state law directly regulates the federal government only if it imposes a substantial burden on federal operations, holding that there is no de minimis exception to intergovernmental immunity. The court also rejected California’s argument that Section 10 of the Act was a generally applicable law that only incidentally affected federal operations, finding that the provision was neither generally applicable nor incidental in its effect. Finally, the court rejected California’s reliance on the case-specific immunity available to individual federal officers, explaining that intergovernmental immunity protects the federal government itself from any direct state regulation, regardless of whether an individual officer could establish an immunity defense in any specific case.
As a result of this ruling, California, its governor, and its attorney general are barred from requiring non-uniformed federal law enforcement officers operating in the state to visibly display identification while performing federal law enforcement duties or from subjecting any such officers not displaying that identification to criminal prosecution.
Liebert Cassidy Whitmore attorneys are closely monitoring developments in relation to this Special Bulletin and are able to advise on the impact this could have on your organization. If you have any questions about this issue, please contact our Los Angeles, San Francisco, Fresno, San Diego, or Sacramento office.