President Donald Trump took a hard swipe at CNN commentator Don Lemon on Wednesday, calling into question his intelligence.

Trump reacted to Lemon's appearance at Tuesday's Democratic presidential debate by highlighting a question in which Lemon insinuated Trump is a racist.

Trump tweeted:

"CNN's Don Lemon, the dumbest man on television, insinuated last night while asking a debate 'question' that I was a racist, when in fact I am 'the least racist person in the world.' Perhaps someone should explain to Don that he is supposed to be neutral, unbiased & fair . . ."

He continued:

". . . or is he too dumb (stupid) to understand that. No wonder CNN's ratings (MSNBC's also) have gone down the tubes – and will stay there until they bring credibility back to the newsroom. Don't hold your breath!"

Democrats and other members of the political left have blasted Trump over his comments about Baltimore and Rep. Elijah Cummings, D-Md., whose district includes portions of Baltimore. Trump and his defenders say he was not being racist when he highlighted some of the living conditions in the city, but critics say the remarks were race-based.

In an interview broadcast Tuesday, Trump wrote off the racism claims and said the term is thrown around too often.