Governor Newsom warned that if Donald Trump sends National Guard or federal troops into San Francisco, California will sue immediately. He stated that such a deployment would be “a direct assault on the rule of law,” arguing the federal government lacks justification, oversight, or respect for state sovereignty.

State and local officials pointed out that San Francisco’s violent crime rates are dropping, with the city seeing a 22 % decrease in violent crime and a 45 % drop in homicides since 2019. They argued a military deployment would be unnecessary, ineffective, and even counterproductive—especially given that the San Francisco Police Department and other local agencies already have crime under relatively good control.

The legal basis for the opposition hinges on the argument that the President and federal defense apparatus cannot simply deploy troops into a state without the governor’s consent when the state is not facing an insurrection, rebellion, or invasion. Newsom and Attorney General Rob Bonta have filed lawsuits and amicus briefs challenging earlier federal deployments of troops—such as those in Los Angeles and Oregon—that they argue violated the Posse Comitatus Act and other provisions limiting domestic military enforcement.

In short: the dispute reflects deeper tensions between federal authority and state sovereignty, especially as to when and how the military may be used domestically. Governor Newsom portrays the proposed deployment as politically motivated and legally dubious, while the Trump administration contends it is within its rights to use federal or Guard forces for law enforcement assistance.