08.11.2025 - 20:36 [ Northeastern.edu ]

What is the Posse Comitatus Act, and how does it apply to Trump’s deployment of the National Guard in California and Washington, D.C.?

(September 9, 2025)

Dan Urman, director of the law and public policy minor at Northeastern University, who teaches courses on the Supreme Court, says the National Guard is often caught between state and federal authority. The guard generally reports to their respective state governors, “but if they get called into federal service, then the Posse Comitatus Act applies to them.”

“To work around this, presidents can ask governors to deploy their state’s National Guard members,” Urman says.