Left-wing Democrats have caused American politics to be dominated by political correctness and patrol those who dissent from their norms, according to Dr. Charles Kesler.

The left thrives on P.C. culture and uses it as a type of moral compass, Kesler, a professor of government at Claremont-McKenna College in California, claimed in an interview airing Sunday on "Life, Liberty & Levin."

"What you see in the phenomenon of political correctness -- which is so powerful -- in a way, it came from the universities, but now it is utterly dominating American politics too," he said.

MARK LEVIN: TRUMP'S COMMENTS ABOUT THE 'SQUAD' WERE ADDRESSING 'CONTENT OF THEIR CHARACTER,' NOT RACE

"If you look at the Democratic presidential candidates, if you look at the 'squad' in Congress, their agenda is driven by political correctness, and political correctness means you hate and cannot tolerate the imperfection -- the moral imperfection -- of your fellow Americans."

Nodding to Hillary Clinton's monikers for supporters of President Trump, Kesler claimed many liberals see "deplorables" and "irredeemables" as people, "who have not evolved."

"We're all supposed to be evolving together into a more perfect union -- as President Obama liked to say -- but the fact [is] that we're not," he said.

Many liberal Democrats, he added, are not receptive to the ideologies of conservatives and center-right moderates.

"The fact that there are these recalcitrant people who insist on ruling themselves [and] having a different kind of government, fundamentally, than the kind that we want and that we think history promises -- the left is not prepared for that," he told host Mark Levin.

CLICK TO GET THE FOX NEWS APP

"It's become kind of... a Medieval established religion. There's an inquisition, there's an index of forbidden books and forbidden thoughts which you're not supposed to read or think.

"There is a strict moral patrol to make sure that you are not caught thinking things you shouldn't be thinking or saying things you shouldn't say. And it's the antithesis of freedom."

However, Kesler claimed some classical liberals are looking at the leftward shift in the Democratic Party and not agreeing with what they are seeing.

They, "are looking around them and saying we don't recognize the America that these people are leading us towards. It doesn't seem to be a free country anymore."