The death of George Floyd has sparked a massive protest movement across the US, some of which have devolved into riots. As a result, the National Guard has been called to intervene in many states.President Trump has suggested that the US military might have to intervene if governors and mayors don’t adequately suppress the riots. On May 30th, Trump posted the following tweet. “Crossing State lines to incite violence is a FEDERAL CRIME! Liberal Governors and Mayors must get MUCH tougher or the Federal Government will step in and do what has to be done, and that includes using the unlimited power of our Military and many arrests. Thank you!”READ: China National Security Law Angers Pro-Democracy AdvocatesLaw professor Richard Painter argued on Twitter that Trump couldn’t intervene with the military because of the Posse Comitatus Act of 1878, which he says states the military cannot be used unless “under circumstances expressly authorized by the Constitution or Act of Congress.”University of Texas law professor Steve Valdeck disagrees with Mr. Painter. Over Twitter, Professor Valdeck wrote that the act “does *not* prevent domestic use of the military for law enforcement. It prevents such use of the military only *without statutory authorization.* And several statutes already authorize use of federalized guard or federal regulars for riot control.”Trump’s post led to concerns that he might try to impose martial law in parts of the US. Using the military to enforce civilian law means it assumes the responsibility for enforcing the entire legal system and often includes the suspension of rights.