Joe Scarborough and Mika Brzezinski spar with Bill Kristol. MSNBC MSNBC host Joe Scarborough and conservative commentator Bill Kristol got into a heated exchange on Thursday over whether the hosts of "Morning Joe" were complicit in Donald Trump's rise within the GOP.

The confrontation escalated when "Morning Joe" cohost Mika Brzezinski disputed Kristol's argument that Trump's nomination was a "fluke," saying Republicans "need to come clean on themselves" about their role in accepting Trump as the de facto leader of the party.

Kristol shot back by sarcastically suggesting that the "Morning Joe" hosts hadn't adequately held the real-estate magnate accountable for tough questions in the months after Trump launched his presidential bid.

"This show was really tough on Trump in late 2015, early 2016. Are you going to pretend that? If that's you're way of rewriting history, that's on you guys," Kristol said.

He added: "A lot of people accommodated Donald Trump at different times. But I'm not going to get into it."

Scarborough and Brzezinski immediately snapped at Kristol, citing an instance in which Scarborough cut to a commercial break when Trump refused to answer one of his questions.

"Please don't come on my air and lie," Scarborough said. "I can't even believe you're doing this. I don't know why you're so bitter. You're practically crying. You're practically crying."

Kristol reiterated that he was "upset" about Trump's nomination and accused the hosts of thinking "it's amusing that Donald Trump's the nominee."

"You treated him that way when he called in? Is that right? You treated him tough, you asked him those tough questions," Kristol said sarcastically.

Scarborough then went off on Kristol, saying he never supported Trump and that he compared the Republican presidential candidate to Adolf Hitler on multiple occasions.

"You're bitter. You come on here practically crying. We've got it on tape. You're screaming at Mika — you don't even know what she's going to say," Scarborough said.

"While you're attacking me personally, I said from the beginning I would never vote for him," Scarborough said. "I said I was voting for Jeb Bush, and I said I was voting for John Kasich. Then we said after the Muslim ban that this is what Germany looked like in 1933. ... I'm sorry we were easy on him. If comparing him to Hitler in 1933 is going easy on him — that was three months before anyone voted — then we were easy on him then."

Kristol is hardly the first to suggest that the "Morning Joe" hosts were too accommodating of Trump.

Many critics early in the campaign charged the MSNBC hosts of being soft on Trump, who Scarborough and Brzezinski predicted before many other pundits could be successful in the Republican primary.

Scarborough admitted in 2015 that he'd offered Trump debate preparation advice. And during an interview before the New Hampshire primary in February, Trump himself characterized Scarborough and Brzezinski on air as "supporters," though both hosts quickly attempted to distance themselves from Trump's assertion.

Still, the hosts' criticism of Trump over issues such as his plan to bar Muslims from entering the US appeared to get under the nominee's skin.

In a series of tweets earlier this year, the Republican presidential nominee slammed the MSNBC hosts over their criticism of his brash campaign style, and suggested that he would share information about a potential romantic relationship between the two hosts, though Trump never provided any evidence to support his claim.