Conservative columnist and prominent Republican commentator George Will said Sunday he has “left the Republican Party for the same reason he joined it” and that he felt let down by the party and the message its top leaders are sending.

Will, speaking on “Fox News Sunday,” said he started doubting the party after Trump became the presumptive nominee and had a summit meeting where House Speaker Paul Ryan “stressed their common principles and said their vast shared ground was much more important than their differences.

“That was puzzling doubly so because Paul Ryan still didn’t endorse him,” Will said. “After Trump went after the Mexican judge from northern Indiana, then Paul Ryan endorsed him and I decided that, in fact, that this is not my party anymore. I changed my registration to unaffiliated 23 days ago.”

Trump tweeted his reaction to the news Sunday, writing, “George Will, one of the most overrated political pundits (who lost his way long ago), has left the Republican Party. He’s made many bad calls.”

Will responded, “He (Trump) has an advantage on me because he can say everything he knows about any subject in 140 characters and I can’t.”

Will has been a persistent critic of Trump and recently wrote a column urging Republican donors to “save their party by not aiding its nominee.”

“Events already have called his bluff about funding himself and thereby being uniquely his own man,” Will wrote in his Washington Post column on Wednesday. “His wealth is insufficient. Only he knows what he is hiding by being the first presidential nominee in two generations not to release his tax returns. It is reasonable to assume that the returns would refute many of his assertions about his net worth, his charitableness and his supposed business wizardry.”

Trump fired back, denouncing Will in a Twitter tirade -- just as he had in the past.

“You know he looks smart because he wears those little glasses,” Trump said at a November rally. “If you take those glasses away from him, he’s a dummy.”