Trump Says He May Invoke br the Insurrection Act, br Here's What to Know About It In prepared remarks in the br White House Rose Garden on Monday, br President Donald Trump threatened to deploy the br U.S. military to put down violent protests in U.S. cities. If Trump does deploy the U.S. military, br he will do so under the Insurrection Act, a law br signed by President Thomas Jefferson in 1807. The last time the act was invoked was in br 1992 during the L.A. riots. It was also used in 1968 br following the assassination of Dr. Martin Luther King. Trump stated that he would deploy br the U.S. military, regardless of whether br state official requested deployment. In order to do this, Trump must br first issue an order for "insurgents" br to disperse in a clearly laid out time frame. The Insurrection Act allows br unrequested deployment to quell br "unlawful assemblages," rebellion or br when the laws become unenforceable. However, the Posse Comitatus Act of br 1878 prohibits the deployment of military troops br for use as police forces. Critics of Trump's use of the br Insurrection Act include NY Governor br Andrew Cuomo and Illinois Governor J.B. Pritzker.