Defense Secretary Mark Esper said in a news conference on Wednesday that he did not support invoking the 1807 Insurrection Act to quell protests using the military, saying National Guard troops are sufficient. Esper said active-duty troops should be a last resort, angering White House officials and Trump for what they regarded as a matter of breaking rank.

Trump confronted Esper later that day in the Oval Office during a meeting with Vice President Mike Pence, Attorney General William Barr and General Mark Milley, head of the Joint Chiefs of Staff. The president privately asked advisers whether Esper could still be effective in his position, according to two people familiar with the matter. But Trump’s pique at Esper seemed to blow over, one of the people said.

The standoff, however, was soon overshadowed by a scathing denunciation from Esper’s predecessor, James Mattis.

Mattis said in a statement that he was “angry and appalled” by the events of the past week, criticizing Trump for allowing protesters to be violently dispersed from Lafayette Square in front of the White House before he walked to a historic church to hold a Bible in front of cameras. It was an abuse of power that made a “mockery of our Constitution,” Mattis said.

The double-barreled rebuke from his current and former defense chiefs elevates the pressure on Trump as he falters in handling a pair of crises: a raging pandemic that has killed more than 100,000 Americans, and protests over a painful legacy of racial inequality, injustice and police brutality following the killing of an unarmed black man at the hands of law enforcement in Minneapolis.

With Trump’s poll numbers sinking, his re-election challenger, Joe Biden, is attempting to seize on the president’s struggle to confront those challenges just five months before voters cast ballots. Mattis’s criticism echoed attacks leveled on Trump by Biden, but the former defense chief’s key role in the president’s original national security cabinet gives him a standing few outsiders could ever claim.

“Donald Trump is the first president in my lifetime who does not try to unite the American people—does not even pretend to try,” Mattis, a retired Marine general, wrote in his statement.

“Instead he tries to divide us. We are witnessing the consequences of three years of this deliberate effort. We are witnessing the consequences of three years without mature leadership,” he wrote. “We can unite without him, drawing on the strengths inherent in our civil society. This will not be easy, as the past few days have shown, but we owe it to our fellow citizens; to past generations that bled to defend our promise; and to our children.”

Trump lashed out in a pair of tweets mocking Mattis’s military service and his nicknames, calling him “the world’s most overrated General.”

The sharply worded and unprecedented rebuke from Mattis only adds to the pressure on the president, who this week threatened to dispatch active duty troops to quash protests and drew widespread condemnation after the clearing of Lafayette Square.

Esper Criticism

The president made no public appearances on Wednesday, as the White House was further fortified with law enforcement personnel brought to Washington by the Bureau of Prisons. Trump gave a pair of interviews to friendly media figures, including his former press secretary Sean Spicer, that touched only briefly on the crisis gripping the nation.

He downplayed the protests and again reiterated his pledge to send in troops, in particular to New York City. In a briefing for reporters, White House Press Secretary Kayleigh McEnany would not directly say that Esper retained Trump’s confidence.

The current defense secretary drew Mattis’s ire as well. Without naming Esper, Mattis cited military jargon the defense secretary and other top officials had used in describing plans to confront protesters.

“We must reject any thinking of our cities as a ‘battlespace’ that our uniformed military is called upon to ‘dominate.”’ Mattis wrote. “We know that we are better than the abuse of executive authority that we witnessed in Lafayette Park. We must reject and hold accountable those in office who would make a mockery of our Constitution.”

Lincoln Comparison

While Trump has condemned Minneapolis police for the death of the unarmed black man, George Floyd, which set off the protests last week, he has not responded to broader demands to address racial injustice and reform U.S. policing. Instead, Trump has demanded governors “dominate” protesters in the streets and has compared himself favorably to Abraham Lincoln, saying he’s the only president who may have done more for black Americans than him.

Mattis stepped down 18 months ago after Trump abruptly announced on Twitter that he wanted to pull troops from Syria, but he was a hugely influential member of the president’s first national security cabinet.

Trump was so eager to unveil his nomination of Mattis after the 2016 election that he announced the plans at a campaign-style rally. He introduced the former head of U.S. Central Command by a moniker — “Mad Dog” — and called him “one of the most effective generals that we’ve had in many, many decades.”

It remains to be seen if Mattis’s rebuke will have lasting political repercussions, but it strikes at the heart of what the president has pitched as one of his strengths: his fulsome praise of the military as part of his “America First” approach to the world, even while he frequently criticizes the national security establishment for allegedly trying to undermine his administration.

Resignation Letter

Despite Trump’s praise of Mattis when he took office, by the end of the defense chief’s tenure their relationship was shattered. Upon his departure, Mattis issued a blunt resignation letter that amounted to a rebuke of Trump’s “America First” mantra.

“We must do everything possible to advance an international order that is most conducive to our security, prosperity and values, and we are strengthened in this effort by the solidarity of our alliances,” Mattis wrote at the time. “Because you have the right to have a Secretary of Defense whose views are better aligned with yours on these and other subjects, I believe it is right for me to step down from my position.”

Days later, Trump lashed out at Mattis, saying “What’s he done for me?” Singling out the U.S. quagmire in Afghanistan, Trump added, “How has he done in Afghanistan? Not too good.”

‘I’ll Take Care of It’

Wednesday’s events unfolded in rapid fashion. Mattis’s scathing statement landed as Trump renewed his threat to send in the military to quash protests during an interview with Spicer, now a host for NewsMax TV, a conservative outlet. Trump called ongoing protests in New York a “disaster.”

“And we could help them a lot, they have to ask,” Trump told Spicer. “If they don’t get it straightened out soon, I’ll take care of it.”

At the same time, protesters continued to wind through the streets of Washington demanding justice for Floyd, who died after an officer knelt on his neck for more than eight minutes. The officer has since been charged with murder, and three other officers who stood by as Floyd died were charged Wednesday as accomplices.

Photos of the Washington demonstration on Wednesday showed protesters laying down on Pennsylvania Avenue, which runs between the White House and Capitol Hill and in front of Trump’s hotel. They lay down for eight minutes.