Why Trump Can Invoke the Insurrection Act

As he spoke from the Rose Garden Monday evening, the booming sounds of police breaking up nearby protests clearly audible over his remarks, President Trump’s message was unmistakable: If states failed to quell the riots that have followed the death of George Floyd at the hands of Minneapolis police, he would do it for them.
“We are ending the riots and lawlessness that has spread throughout our country,” Trump said. “Mayors and governors must establish an overwhelming law enforcement presence until the violence has been quelled. If a city or state refuses to take the actions that are necessary to defend the life and property of their residents, then I will deploy the United States military and quickly solve the problem for them.”
This threat, coupled with Trump’s eager rhetoric about sending “heavily armed soldiers, military personnel, and law enforcement officers” into America’s streets, was met with horror by many of the president’s opponents. Sen. Ron Wyden of Oregon denounced the remarks as a “fascist speech” that “verged on a declaration of war against American citizens.” Armchair pundits like Cary Elwes of The Princess Bride fame announced that such an act would be illegal under the Posse Comitatus Act of 1878, “which prohibits military enforcing domestic policies.”
But these denunciations are largely misguided—at least as a matter of law. The law Trump has flirted with invoking, the Insurrection Act of 1807, grants the president discretion to deploy federal troops to uphold domestic law in places where he deems public order has collapsed. Under the current legislative framework, it will likely be political concerns—not legal ones—that will determine whether Trump ultimately decides to send in the military.