The unfounded posts have gained traction in the wake of the US Capitol breach on Wednesday that engulfed the nation’s capital in chaos and left five dead, including an officer with the US Capitol Police.
While the law provides ample legal footing for presidents to deploy the military if they so choose, in practice it’s been used sparingly. The most notable application of the law was perhaps its invocation to enforce desegregation in the 1950s.
The main provision of the Insurrection Act states that troops can only be deployed to an American state by the President if the governor or state legislature requests it.
Another provision of the law, however, outlines that under certain limited circumstances involved in the defense of constitutional rights, the President can send troops unilaterally.
How have presidents used the law?
The Insurrection Act hasn’t been invoked since 1992 during the riots in Los Angeles that followed the acquittal of four white police officers in the beating of Rodney King, a black man, according to the Congressional Research Service.
Congress amended the law after Hurricane Katrina in 2006 to give more clarity about its use during natural disasters, but dropped some of those changes a year later after objections by state governors who did not want to cede their authority.
There are examples of presidents using troops over the objections of governors, as Dwight Eisenhower (and later John F. Kennedy and Lyndon B. Johnson) did during the Civil Rights era.
In particular, Eisenhower invoked the Insurrection Act when he federalized the Arkansas National Guard and then sent the 101st Airborne Division into Little Rock to integrate the schools.
But there are exceptions in that law for insurrection of rebellion and, after the Patriot Act, for terrorism.
Has Trump ever threatened to invoke it?
While he’s never invoked the law, the President did threaten to use it last year.
“If the city or state refuses to take the actions that are necessary to defend the life and property of their residence, then I will deploy the United States military and quickly solve the problem for them,” Trump said at the time, though he never did.
CNN’s Zachary B. Wolf contributed to this report.