Speaking from the Rose Garden on Monday evening, Donald Trump issued an unprecedented threat from an American president: that he would send thousands of heavily armed soldiers into Washington, D.C., to quell protests and would follow by invoking the Insurrection Act to deploy the military into other U.S. cities if mass protests against police brutality continued.

As he spoke, federal law enforcement officials working alongside military police officers fired projectiles and tear gas upon American citizens protesting peacefully just yards from the White House so that the president could be photographed holding up a Bible in front of a nearby church.

Democrats and a former military official condemned the presidents surreal display of authoritarianism. Rep. Jennifer Wexton (D-Va.) called Trumps orders the actions of a dictator. Rep. Pramila Jayapal (D-Wash.), co-chair of the Progressive Caucus, said Trump was unleashing authoritarian violence on our fellow Americans. And retired Gen. Martin Dempsey, a former chairman of the Joint Chiefs of Staff, declared on Twitter, Our fellow citizens are not the enemy.

Other members of Congress, including Sen. Ron Wyden (D-Ore.) and Reps. Mark Pocan (D-Wis.) and Val Demings (D-Fla.), likened Trumps speech to fascism. Rep. Don Beyer (D-Va.) called his actions naked authoritarianism.

Hes using the American military against the American people, presumptive Democratic presidential nominee Joe Biden tweeted. Sen. Elizabeth Warren (D-Mass.), a recent contender for the nomination and a possible vice presidential selection, tweeted, Lives and our democracy are in danger.

Elected Republicans were mostly silent; a few suggested that Trump adjust his tone .

Twenty minutes before a 7 p.m. curfew in D.C. went into effect and moments after Attorney General William Barr observed the police line near the White House, federal law enforcement fired tear gas into a peaceful crowd as protesters raised their hands and chanted, Dont shoot.

It was absolutely out of nowhere, Diane May, one of the protesters, told HuffPost. No one was throwing anything. Everyone was in the space that was provided for us and they just started advancing on us.

The violent attack on protesters was an apparent effort to clear the area in front of the White House so Trump could walk to St. Johns Episcopal Church to pose for a picture at the historic church, which was burned during unrest the previous evening. The president wanted to project a show of strength after The New York Times reported Sunday that he had retreated to a bunker in the White House that intended for use during terrorist attacks.

Bishop Mariann Budde, the Episcopal bishop for the Diocese of Washington, told a Washington Post reporter that she was outraged and that church officials were never told they would be clearing with tear gas so they could use one of our churches as a prop. On CNN, she said Trumps message was antithetical to the teachings of Jesus and everything that our churches stand for.

To think that people could have gotten seriously injured or even killed just for a pose by a church that didnt even want him there is outrageous, said May, 33.

Washington Mayor Muriel Bowser called the actions of federal police shameful and said they acted without provocation. An official in Arlington, Virginia, which was assisting with the police response, said they ordered Arlington Police out of the city, saying a mutual aid agreement was abused to endanger their and others safety for a photo op.

In the televised Rose Garden speech, after days of police violence against civilians protesting police killings of Black Americans, Trump threatened to invoke the 213-year-old Insurrection Act to deploy the military into cities. He encouraged cities and states to deploy the National Guard in sufficient numbers that we dominate the streets. In places where mayors and governors do not respond aggressively enough to quash protests, Trump said, I will deploy the United States military and quickly solve the problem for them.

As Trump spoke, police officers used force in an attempt to suppress protests in major cities throughout the country, including New York, Philadelphia, San Francisco, Los Angeles, Chicago, Atlanta, Seattle and Louisville, Kentucky. At least 40 cities imposed curfews , making it easier for police to arrest peaceful demonstrators on curfew violation charges.

Defense Secretary Mark Esper told governors on Monday to approach the protests like a battle against their citizens. I think the sooner that you mass and dominate the battle space , the quicker this dissipates and we can get right back to the right normal, Esper said in a White House call with governors, according to audio obtained by The Washington Post.

Trumps threat to send heavily armed federal military personnel into American cities to enforce order against the wishes of their elected officials is of questionable legality. The Posse Comitatus Act limits the federal government from enforcing domestic policy with military personnel. The Insurrection Act only permits the president to federalize the National Guard and deploy other U.S. armed forces at the request of a state government or if a state government is incapable of protecting its citizens. It has only been invoked in a handful of cases, including to protect the Little Rock Nine in Arkansas in 1957 and in the midst of the 1992 Los Angeles uprising over acquittals in the Rodney King beating.

The American Civil Liberties Unions Hina Shamsi called the plan irresponsible and dangerous and said that no level-headed governor is asking for an even more militarized response to civilian protests against police brutality and systemic racism.

President Trump is not a dictator and he doesnt have the right to unilaterally deploy US military across American states, tweeted New York State Attorney General Tish James.

Although that may legally be true, Barr has an extraordinarily wide view of executive power, and the Justice Departments Office of Legal Counsel has imposed few limits of Trumps power, justifying many of his whims throughout his presidency.