The dispute centers on Section 10 of California's No Vigilantes Act, enacted September 20, 2025, in response to what the legislature described as the United States's broad immigration enforcement efforts. The law requires any non-uniformed federal law enforcement officer operating in California to visibly display identification — including their agency and either a name or badge number — while performing enforcement duties. Officers whose willful and knowing violation of the requirement is established face misdemeanor prosecution under California law.
The United States sued California, Governor Gavin Newsom, and Attorney General Rob Bonta on November 17, 2025, arguing that the identification mandate facially violates the Supremacy Clause by directly regulating federal operations. The district court, presided over by Judge Christina A. Snyder of the Central District of California, declined to enjoin the provision. The district court concluded both that the United States had not met its burden to show enforcement would interfere with or take control of federal law enforcement operations, and that the United States had not shown its identification practices were essential to federal law enforcement operations such that state regulation would interfere with or control those functions.
The Ninth Circuit panel — Judges Jacqueline H. Nguyen, Mark J. Bennett, and Daniel P. Collins, with Judge Bennett authoring the opinion — held that the district court asked the wrong question. The interference-with-operations standard applies to state regulation of federal contractors and third-party employers, not to direct regulation of the federal government itself. Because Section 10 expressly applies to federal officers and purports to override the federal government's power to determine whether, how, and when to publicly identify its agents, the panel held it constitutes direct regulation of governmental functions, which the Supremacy Clause forbids regardless of the degree of interference or whether the regulated activities are essential to federal operations.
The panel also rejected California's argument that the court should weigh the public safety concerns that prompted the Act's passage. Because the United States demonstrated a likelihood of success on the Supremacy Clause claim, the panel held that irreparable harm necessarily results, and that the public interest and balance of equities tip decisively in favor of the injunction, with no further balancing required.
The panel distinguished Section 10 from general laws regulating conduct any ordinary citizen could perform — the kind of broadly applicable state rules the Supreme Court has suggested may reach federal actors. Section 10, the panel noted, applies exclusively to law enforcement agencies and their officers, making it a regulation of conduct reserved to sovereigns rather than a neutral rule of general applicability.
The injunction entered February 19, 2026, as a temporary administrative measure, remains in effect. California, the Governor, and the Attorney General are enjoined from applying or enforcing Section 10 of the No Vigilantes Act against federal agencies and officers pending further order of the court.