By Vanguard Staff
In opposition to the Trump administration’s use of military force on domestic soil, a coalition of more than 50 local governments and officials from across the country filed an amicus brief on Sunday urging the U.S. Court of Appeals for the Ninth Circuit to block President Donald Trump’s federalization and deployment of the California National Guard.
The case, Newsom, et al. v. Trump, et al., No. 25-3727, pits California Governor Gavin Newsom and other state officials against the federal government in a high-stakes legal showdown over states’ rights, civil liberties, and the limits of presidential power.
The brief, submitted in support of California’s opposition to the federal government’s emergency motion to stay a district court injunction, was filed by the San Francisco City Attorney’s Office and co-counseled by the Public Rights Project and the San Francisco-based law firm Keker, Van Nest & Peters LLP. Four jurisdictions—Chicago, Santa Clara County, Alameda, and Santa Monica—are represented by Keker in the filing.
Dozens more cities, counties, and elected officials joined the brief, underscoring the broad alarm among local governments over what they view as a dangerous federal incursion into core local responsibilities.
At issue is a June 7, 2025, memorandum from President Trump directing the Department of Defense to deploy the National Guard and U.S. Marines to respond to protests in Los Angeles.
The deployment was ordered without any request or consent from the State of California or local officials—an action the amici argue is unlawful, counterproductive, and fundamentally incompatible with the principles of American federalism.
The brief contends that the president’s unilateral use of the military to manage protests in California cities violates the sovereign powers of both the state and its municipalities, disrupts law enforcement operations, and threatens to inflame tensions on the ground.
The district court, in a ruling issued by Judge Charles Breyer, temporarily enjoined the deployment, concluding that it lacked legal authority and posed significant harm to the public interest. That ruling was subsequently stayed pending appeal, prompting the current emergency proceedings.
In their filing, the amici emphasize that local governments have extensive experience managing protests and demonstrations—including those that escalate—and are better equipped than the military to do so safely, effectively, and in a manner that respects constitutional rights.
“Amici have developed policies and practices that balance the individual rights of their citizens with public safety needs,” the brief explains. “By deploying the California National Guard and the U.S. Marines to respond to protests, appellants have put Amici’s ability to implement these local policing goals and practices in jeopardy.”
The brief warns that military forces are not trained in de-escalation techniques or constitutional policing, and that their presence—particularly when uninvited—can increase the risk of violence, confusion, and miscommunication.
The filing outlines how military deployments interrupt local law enforcement’s chain of command, create jurisdictional overlap, and undermine carefully constructed relationships between law enforcement and local communities.
The amici stress that military deployment should be a measure of last resort, invoked only in the most extreme circumstances—such as foreign invasion or natural disaster—when local and state resources have been exhausted. They argue that the federal government’s current actions not only lack justification but actively harm public safety.
The brief draws on historical and legal precedent to reinforce its arguments, citing Burford v. Sun Oil Co., Nken v. Holder, and Laird v. Tatum to highlight the constitutional tradition of local control over policing. It also references National Federation of Independent Business v. Sebelius, quoting James Madison’s Federalist No. 45 to support the view that police powers should remain with local authorities.
Operationally, the amici outline how many cities—such as San Francisco, Oakland, Madison, and Albuquerque—have adopted detailed protocols for managing public demonstrations that emphasize de-escalation, First Amendment protections, and community engagement.
For example, San Francisco Police Department’s General Order 8.03 outlines principles that prioritize free speech, protect peaceful assembly, and minimize the use of force. These approaches, the brief argues, are the product of years of lived experience and community collaboration, and are precisely what the military lacks.
In addition to policy and training, local law enforcement agencies are subject to oversight and accountability mechanisms—such as body-worn camera mandates, use-of-force reporting, and civilian review boards—that do not apply to federal troops.
In California, Assembly Bill 481 requires law enforcement agencies to publicly report on the acquisition and deployment of military-style equipment, reinforcing public transparency. The federal military operates with no such accountability to local residents.
The brief also points to California’s long-standing mutual aid system, in place since 1961, which allows jurisdictions to request additional support from neighboring law enforcement agencies in emergencies. This system, the amici argue, is designed to ensure coordination and safety during high-stress situations—coordination that was bypassed entirely by the federal government’s unilateral decision to send in troops.
By ignoring both the mutual aid framework and state sovereignty, the federal government’s actions not only disrupt existing public safety strategies, but may also increase the risk of harm to civilians, local officers, and military personnel alike. The brief warns of potential “friendly-fire” incidents and other unintended consequences when multiple uncoordinated agencies operate in the same space.
The list of amici reflects the national significance of the case. In addition to California jurisdictions, the brief is signed by leaders and governments from New York, Illinois, Wisconsin, Maryland, Connecticut, Pennsylvania, Minnesota, and more. Among the signatories are the cities of Baltimore, Minneapolis, New Haven, and Pittsburgh; counties including Montgomery (MD) and Dane (WI); and local elected officials such as prosecutors, city attorneys, councilmembers, and school board members.
The brief notes: “Any protest within their borders could result in the unnecessary and disruptive deployment of military force… absent state and local request, consent, or coordination.”
A ruling by the Ninth Circuit in favor of the federal government would leave open the possibility for future administrations to bypass state and local authority in times of civil unrest, expanding federal control over protest policing in ways that many local governments consider authoritarian and unconstitutional.
By contrast, affirming the lower court’s injunction would reassert the longstanding division between federal and local power and send a clear signal that military involvement in local law enforcement must be rare, justified, and invited.
The Ninth Circuit is expected to issue a ruling following Tuesday’s hearing. The outcome could shape the balance of power between federal and local governments not only in California, but across the country for years to come.
