Donald Trump’s presidential campaign faced a crisis of confidence on Tuesday as Republicans denounced his attacks on a federal judge as racist and grappled with whether to retract their endorsements.

In a remarkable rebuke of the presumptive nominee, Speaker Paul Ryan (R-Wis.) called the candidate’s remarks about Judge Gonzalo Curiel “the textbook definition of racist comments” and described them as “indefensible,” though he did not withdraw his support for Trump.

{mosads}“I regret these comments that he made,” Ryan told reporters at an event on poverty in Washington, D.C. “I think that should be absolutely disavowed.”

The extraordinary statement from Ryan, the highest-ranking Republican in the country, intensified the storm surrounding Curiel, a judge who Trump  has said is biased against him in Trump University proceedings because “he’s a Mexican.”  

Ryan’s condemnation put pressure on other Republicans to do the same, including the vulnerable Senate GOP incumbents who fear losing their seats if Trump’s candidacy implodes.

Sen. Mark Kirk (Ill.), perhaps the most vulnerable Senate Republican up for reelection in 2016, wasted no time in announcing he could no longer vote for Trump. In a searing statement, Kirk called the comments about Curiel “dead wrong” and “un-American.”

“Our president must be fit to command the most powerful military the world has ever seen, including an arsenal of thousands of nuclear weapons,” Kirk said. “After much consideration, I have concluded that Donald Trump has not demonstrated the temperament necessary to assume the greatest office in the world.”

Kirk was the first major Republican to retract his support for Trump over the Curiel controversy, but he might not be the last.

Sen. Lindsey Graham (S.C.) exhorted fellow Republicans to think long and hard about their support for Trump, calling the attacks on Curiel “the most un-American thing from a politician since Joe McCarthy.”

“If anybody was looking for an off-ramp, this is probably it,” Graham said, according to The New York Times. “There’ll come a time when the love of country will trump hatred of [Democratic presidential front-runner] Hillary [Clinton].”

With the damage mounting, Trump made an effort to lower the temperature Tuesday afternoon, issuing a lengthy statement in which he said his remarks about Curiel have been “misconstrued” by the media.

“It is unfortunate that my comments have been misconstrued as a categorical attack against people of Mexican heritage. I am friends with and employ thousands of people of Mexican and Hispanic descent,” the real estate tycoon said. 

“I do not feel that one’s heritage makes them incapable of being impartial, but, based on the rulings that I have received in the Trump University civil case, I feel justified in questioning whether I am receiving a fair trial.” 

Trump declared at the end of his statement that he does “not intend to comment on this matter any further,” but his statement, while taking a different tone, appeared unlikely to stanch the bleeding.

Virtually every vulnerable GOP senator was asked Tuesday about whether he or she would support Trump given what the Speaker described as racist remarks. That dynamic left some Republicans frustrated with Ryan. 

“His comments poured gasoline on the fire and put every Republican in an incredibly uncomfortable position. It was entirely avoidable,” said one Senate GOP aide.

Senate Majority Leader Mitch McConnell (R-Ky.) declined to go as far as Ryan in saying the comments about Curiel were racist but scolded Trump for drifting off message and putting at risk what he called an “eminently winnable” election. 

“My advice to our nominee would be to start talking about the issues that the American people care about and to start doing it now,” he told reporters after meeting with Senate Republican colleagues over lunch.

“In addition to that, it’s time to quit attacking various people that you competed with or with various minority groups in the country and get on message,” he said.

There’s a growing sense of resignation among GOP lawmakers that Trump isn’t going to change his ways and that advice from Washington is likely to have little effect.

“I held out hope that the new Donald is different from the old Donald — but looks about the same,” said Sen. Jeff Flake (R-Ariz.), who has said he can’t yet support Trump. “He turns 70 [next] week. Most of us after 30 find it tough to change a lot.”

Democrats pounced on Ryan’s comments to pressure GOP candidates to disavow Trump more explicitly.

“I just think at a certain time you have to put your country ahead of your party,” said Sen. Claire McCaskill (D-Mo.), a surrogate for Clinton, echoing Graham’s remarks.

“If you’ve got someone that flawed and that dangerous and unstable as your nominee …  I’m not saying you have to love up on Hillary Clinton, but this notion that they’re saying, ‘Yeah he’s a racist, but he’s our racist’ — that’s really weird,” McCaskill added.

At Trump’s urging, some of his allies have begun to make the case that it’s members of the media — not the businessman — who are engaging in racist attacks. Trump surrogate Jeffrey Lord, a CNN contributor, even threw that charge back at Ryan.

“Speaker Ryan is wrong,” Lord said. “Speaker Ryan has apparently switched positions and is supporting identity politics, which is racist. I am astonished.”

But many Senate Republicans, even some of Trump’s bolder supporters, were not buying that defense.

Sen. James Inhofe (R-Okla.), who earlier criticized Ryan for holding back his endorsement of Trump, said the candidate should apologize.

“I would like to see that,” he said. “He’ll hopefully say something.”

Sen. Richard Burr (R-N.C.) said, “I don’t think there’s any place for racism in this country.”

Sen. Susan Collins (R-Maine), a moderate who has not yet backed Trump, said, “He can apologize to the American people.

“I have not endorsed him. I have always supported the nominee of my party and I hope to be able to in this case, but I have not yet reached that decision,” she said.

McConnell repeated his warning, first issued last week, that Trump risks turning off Hispanic voters from the GOP in the same way Barry Goldwater, the 1964 Republican presidential nominee, alienated African-American voters from his party for decades.

“I was worried that we would do to the Latino vote what was done to the African-American vote by defining our party in such a way that we could not reach out to what has become the nation’s largest minority group,” he said. “I am worried about that. I said that last week, and I’ll say it again today.” 

Jordain Carney contributed.