Retired Marine Gen. John Kelly, who was Donald Trump’s longest-serving White House chief of staff, has warned that his former boss, if elected again, would govern like a dictator, that he lacks empathy, and that he has no understanding of the U.S. Constitution.

While other Trump administration officials have criticized the former president, including from the stage of the Democratic National Convention in August, Kelly is perhaps the most high-profile, telling the New York Times in an interview published two weeks before election day that he had grave concerns about Trump’s fitness for office.

“Certainly the former president is in the far-right area, he’s certainly an authoritarian, admires people who are dictators — he has said that. So he certainly falls into the general definition of fascist, for sure,” Kelly said.

In the interview, the former chief of staff said he had admonished Trump multiple times for making admiring statements about Adolf Hitler, such as, “You know, Hitler did some good things, too.”

Kelly told the New York Times in the recorded interview that he decided to go on the record because he was deeply troubled by Trump’s suggestion in a Fox News interview this month that he might try to use the U.S. military against domestic foes and “radical-left lunatics” such as Rep. Adam B. Schiff (D-Burbank), whom he called an “enemy from within.”

Trump has since expanded on those comments, calling his Democratic opponents a bigger threat to the country than China or Russia.

Steven Cheung, a spokesperson for the Trump campaign, said in a statement that Kelly “has totally beclowned himself with these debunked stories he has fabricated because he failed to serve his President well while working as Chief of Staff and currently suffers from a debilitating case of Trump Derangement Syndrome.”

In an interview with the Atlantic also published Tuesday, Kelly recalled Trump saying he needed “German generals” who would be loyal to him.

“Surely you can’t mean Hitler’s generals?” Kelly said he asked. “And he said, ‘Yeah, yeah, Hitler’s generals.’”

Vice President Kamala Harris addressed the Kelly interviews in brief remarks on Wednesday from her official residence, the Naval Observatory in Washington, D.C., She said the former chief of staff’s remarks were further evidence that Trump “is increasingly unhinged and unstable” and that “people like John Kelly would not be there to be the guardrails” against his worst impulses in a second term.

Harris said the Kelly interview, along with the “enemies from within” comments, show that Trump wants a military that would be more akin to “a personal militia” that is loyal to him personally and would “obey his orders even when he tells them to break the law or abandon their oath to the Constitution of the United States.”

“Let’s be clear,” Harris said, “about who he considers to be the enemy from within: Anyone who refuses to bend a knee or dares to criticize him would qualify, in his mind, as the enemy from within. Like judges, like journalists, like nonpartisan election officials. It is deeply troubling and incredibly dangerous that Donald Trump would invoke Adolf Hitler, the man who is responsible for the deaths of 6 million Jews and hundreds of thousands of Americans.”

In his interview with the New York Times, Kelly, whose son was a Marine killed in 2010 while fighting in Afghanistan, confirmed previous reports that Trump had described U.S. soldiers who died on the battlefield as “losers and suckers” and that he was disgusted by physically disabled veterans.

“Certainly his not wanting to be seen with amputees — amputees that lost their limbs in defense of this country fighting for every American, him included, to protect them, but didn’t want to be seen with them. … He would just say: ‘Look, it just doesn’t look good for me,’” Kelly said.

Kelly served 46 years in the Marines, from the Vietnam War to the rise of Islamic State, making him the U.S. military’s longest-serving general when he retired in January 2016.

He was one of four White House chiefs of staff during the Trump administration, holding the position from July 2017 through January 2019. Before that, he was the Homeland Security secretary in the Trump administration.

When Trump picked him to head Homeland Security, and then serve as his White House chief of staff, officials from the Pentagon to Capitol Hill expressed hope that he would be one of the “adults in the room” to manage the mercurial and vindictive president.

Kelly was at the forefront of some of the Trump administration’s most controversial immigration and security policies, including separating migrant children from their parents at the U.S.-Mexico border.

In the New York Times interview, Kelly noted that he was not endorsing a candidate. He said he agreed with many of Trump’s policies but that “it’s a very dangerous thing to have the wrong person elected to high office.”