As Donald Trump's former bagman Michael Cohen warned in 2019, "I fear that if he loses the election in 2020 that there will never be a peaceful transition of power."
The president has insisted he told former defense secretary James Mattis to resign, which has been disputed.
The condemnation from former Defense Secretary James Mattis and the GOP senator add to the growing list of politicos and military figures who have denounced Trump's handling of the civil unrest that has sparked in cities from coast to coast over the death of a black man by a white police officer.
"We must reject and hold accountable those in office who would make a mockery of our Constitution," General James Mattis wrote Wednesday.
"I didn't like his 'leadership' style or much else about him, and many others agree," President Trump tweeted on Wednesday about former defense secretary General James Mattis.
The former national security adviser faces backlash as damning Ukraine book leaks continue.
The former Secretary of Defense responded to President Donald Trump calling him "the world's most overrated general" by calling himself "the Meryl Streep of generals."
Democratic Rep. Adam Schiff joined several GOP lawmakers in condemning President Trump's U.S. troop withdrawal from Syria, warning that ISIS is already beginning its resurgence.
Tens of thousands of protesters descended on the U.S. consulate in Hong Kong on Sunday, calling on the Trump administration to lend more support.
The former secretary of defense said the days of cooperation with Russia are gone and that the U.S. must stand alongside its allies against President Vladimir Putin.
"He's an unusual president, our president is. And I think that especially with, just the rabid nature of politics today, we gotta be careful. We could tear this country apart," the former Marine general said.
Former U.S. Secretary of Defense James Mattis penned a reflective condemnation of his old boss, President Donald Trump, and urged Americans to reject the "tribalism" and divisive rhetoric stirred up by the current administration.
Defense Department officials told Newsweek that Deputy Secretary of Defense Patrick Shanahan would be "great" for the military industrial complex but was not a strategic thinker.
The president has a "great team" of national security advisers around him, Lindsey Graham said, adding that "he just needs to listen" to them.
"I've never registered for any political party," the defense secretary said after Trump called him "sort of a Democrat" on "60 Minutes."
The veteran investigative reporter warned he had "literally hundreds of hours of tapes."
The allegations included having her staffers pick up her laundry and drive her around on snow days.
"The Russian disinformation campaign has already begun," a Pentagon spokeswoman said.
But the technology probably won't be ready for another 10 to 15 years, arms experts say.
Defense Secretary James Mattis is heading to the White House to show President Donald Trump his options for attacking Syria.
The former Pentagon employee shared a video stating Obama was born in Kenya and another suggesting he was the Antichrist.
A top Russian general reportedly intervened to stop an attack from the U.S., preventing a repeat from last month in which many Russians were killed.