President Donald Trump is slamming Don Lemon over a question from Tuesday night's Democratic debate.

In a series of tweets, the president called the CNN anchor, who was one of the debate's moderators, "dumb" and criticized a question Lemon asked that described Trump as bigoted.

"What do you say to those Trump voters who prioritize the economy over the president's bigotry?" Lemon asked Sen. Amy Klobuchar.

Trump took to Twitter Wednesday to comment on the question.

Trump's response:Trump says Democratic presidential opponents would lead to 'economic sinkhole'

"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 tweeted.

In a follow-up tweet, Trump 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!"

During the debate, Klobuchar said: "There are people that voted for Donald Trump before that aren’t racist, they just wanted a better shake in the economy. And so I would appeal to them."

Meanwhile, Beto O'Rourke tweeted on Wednesday: "Donald Trump is a racist." The presidential candidate shared a video from the Tuesday debate in which he calls the president out.

This isn't the first time Trump has questioned Lemon's intelligence. In May, he mocked CNN's Chris Cuomo for "record low" ratings while attacking Lemon as "the dumbest man on television."

"Wow! CNN Ratings are WAY DOWN, record lows. People are getting tired of so many Fake Stories and Anti-Trump lies. Chris Cuomo was rewarded for lowest morning ratings with a prime time spot - which is failing badly and not helping the dumbest man on television, Don Lemon!" the Trump tweet read.

Earlier, in August 2018, he called both basketball star LeBron James and Lemon dumb after James criticized the president in an interview with Lemon on CNN.

“Lebron James was just interviewed by the dumbest man on television, Don Lemon,” Trump tweeted. “He made Lebron look smart, which isn’t easy to do. I like Mike!”

Lemon didn’t mince words when he later talked about the controversy for nine minutes on CNN.

"The president has called a lot of people stupid," Lemon said. "Some of those people are white. But I would just like to note that referring to an African American as dumb — remember this is America — is one of the oldest canards of America’s racist past and present: that black people are of inferior intelligence."

Trump also has made the black Congresswoman Maxine Waters of California a special target of his contempt, repeatedly describing her at rallies and on Twitter as having an "extraordinarily low I.Q."

"Congresswoman Maxine Waters, an extraordinarily low IQ person, has become, together with Nancy Pelosi, the Face of the Democrat Party," Trump tweeted in June 2018. "She has just called for harm to supporters, of which there are many, of the Make America Great Again movement. Be careful what you wish for Max!"

The Democrats' debates continue Wednesday night on CNN.

Late night on the debate:Stephen Colbert compares democratic debate to 'dwarfs offering Snow White a poison apple'

More:CNN's Don Lemon announces engagement to boyfriend Tim Malone