What is the Insurrection Act and how could Trump use it? Here's what to know

False social media posts swirled late Sunday that President Donald Trump in the wake of the U.S. Capitol riots had invoked the Insurrection Act, a law that allows the president to deploy the military to quell rebellion.

Tweets sharing images of military personnel in Washington continued to spread Monday morning and became a trending term on Twitter. However, Trump has not invoked the law.

The law, which has existed in various forms since the time of George Washington and in its current state since the Civil War, allows the president to dispatch the military or federalize the National Guard in states that are unable to put down an insurrection or are defying federal law.

It was last invoked in 1992 by George H.W. Bush during the unrest in Los Angeles after the acquittal of police officers who beat Rodney King.

What is the Insurrection Act?

The Insurrection Act gives the president authority to call on military and National Guard forces to suppress an insurrection if a state requests it, if there is an insurrection that makes it impossible to enforce federal law, or if there is an insurrection or domestic violence that deprives others of their Constitutional rights.

The Act also requires the president to issue a proclamation demanding those participating in the insurrection disperse.

William Banks, a Syracuse University College of Law Board of Advisors Distinguished Professor, said that when thinking about the Insurrection Act, it's important to remember one of the most basic principles of the United States' founding: that the military not be involved in civilian affairs.

"The Insurrection Act lays into U.S. law an exception to that background principle," Banks said.

In most cases, a state would want to rely on National Guard troops in situations of unrest. The Insurrection Act is generally reserved for when "things are really bad," Banks said.

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How does it differ from martial law?

The Insurrection Act is a law while "martial law" is a concept that doesn't have a legal definition in the U.S. "It's not enshrined anywhere," said Thaddeus Hoffmeister, a law professor at the University of Dayton.

Generally, martial law means that the military takes over civilian control of the government, whereas the Insurrection Act applies to specific instances of rebellion or refusal to uphold the law and requires a state's National Guard or the U.S. military to intervene.

"Martial law is essentially the absence of law," Banks added. It would apply to situations where the rule of law has broken down so much that law is no longer in place. "It's really an alien concept" in the U.S., he said.

Read this: Former Capitol Police Chief Steven Sund's request for National Guard backup was denied, he says in interview

How would the Insurrection Act have applied to the Capitol riot?

A deadly mob that Trump incited stormed the Capitol last Wednesday, breaking in, attacking Capitol Police officers and trashing offices as some stormed onto the Senate floor. Congress was meeting to certify the Electoral College vote and President-elect Joe Biden's win. Rioters chanted "Stop the Steal," falsely claiming Trump had won the election.

BuzzFeed News reported Sunday that local lawmakers in the district had received a briefing from the district's attorney general's office in the days before the riots about the implications if Trump were to invoke the Insurrection Act and how it would affect the local police department.

“We had every reason to suspect there would be some sort of trouble,” Phil Mendelson, chairman of the district council told BuzzFeed News, adding “our concern was that it would be fomented by the president who would say: ‘Look, there’s rioting and chaos – we need to take over the police department and bring in the National Guard.’”

Lindsey Walton, director of communications for Mendelson, confirmed to USA TODAY that the memo was presented to the council. "The Chairman indicated the memo was mundane and more of a cautionary thing as opposed to preparatory," she added.

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