The Insurrection Act is a federal law that allows the president to deploy the military and National Guard troops to suppress civil disorder, insurrection or rebellion. It was last used by President George H. W. Bush during the Los Angeles riots after the Rodney King verdict in April 1992.

Gavin Newsom asked the Trump administration on Sunday to rescind its move to deploy 2,000 California National Guardsmen to Los Angeles to subdue immigration protests, accusing the White House of illegally overriding his authority and intentionally inflaming tensions with protesters.

Gov. Gavin Newsom’s office, in a letter to the Trump administration, called the deployment of troops “unlawful” and a “serious breach of state sovereignty.”