David Letterman is adding his name to the long list of celebs who are putting Donald Trump on blast for making disparaging claims about President Obama.

When Letterman found out Dr. Phil, his guest on last night's show, was friendly with Trump, Dave took the opportunity to speak out on what he called The Donald's increasingly racist remarks, including Trump's questioning of not only Obama's birthplace, but whether the President's admittance into Harvard Law School was on his own merit.

“It’s all fun, it’s all a circus, it’s all a rodeo, until it starts to smack of racism. And then it’s no longer fun,” Letterman said to Dr. Phil. “So you thought it was racism?” Dr. Phil asked. “Well, yes,” Dave responded. “Do you consider him to be a racist?”

“I do not,” Dr. Phil said, explaining, “...I don’t think he always thinks everything through. I think sometimes he’s a little from the hip, and I don’t think he has a racist bone in this body.”

Letterman went on to say, “If he comes back on this show, and I am not sure we want him back on this show under these circumstances, he ought to be prepared to apologize just for that kind of behavior.”

Letterman isn't the only icon Trump is turning off. Another celeb recently called him a "pompous @sshole"! See who it was ... after the jump.