Donald Trump is under fire once again for attacking a minority on Twitter. This time it’s one of the people who moderated the CNN debate Tuesday night. There were three moderators. Two were white (Dana Bash and Jake Tapper) and one, Don Lemon, was African-American. Guess which one he criticized? Trump called Lemon “stupid,” and “the dumbest man on television.”

He appears to be attacking Lemon for asking Sen. Amy Klobuchar “What do you say to those Trump voters who prioritize the economy over the president’s bigotry?”

GLAAD remarked:

Don Lemon has built a career out of pursuing and sharing the truth at all costs. Not only is he an esteemed journalist, but he’s a true pioneer for the LGBTQ community. @realDonaldTrump‘s continued attacks on the intelligence of prominent Black Americans are abhorrent and telling.

Conservative commentator Ana Navarro adds:

@IlhanMN, @RepCummings, now @donlemon….Trump keeps doubling-down on his insults against African-Americans. It is not coincidence. It is purposeful. He plans to win by stoking racism and bigotry and division. If you support him, you are supporting that. Own it.

This isn’t the first time that Trump has lashed out at Lemon, questioning his intelligence. Last year after Trump also said Lemon was “the dumbest man on television,” Lemon said:

I would just like to note that referring to an African American as dumb… is one of the oldest canards of America’s racist past and present, that black people are of inferior intelligence.

No response yet from Lemon today.