WASHINGTON — Rival Republican presidential candidates piled on Donald Trump on Saturday for his caustic remarks about a female debate moderator, and the billionaire celebrity candidate backpedaled in an effort to keep his campaign from unraveling.

Trump blasted Fox News anchor Megyn Kelly during a debate in Cleveland on Thursday when she questioned him about insulting comments he had made about women. The backlash to his exchange with Kelly has threatened to knock the wheels off the bandwagon of support that had Trump leading early polls in the race for the Republican nomination for the 2016 election.

Asked about Kelly on a CNN interview on Friday, Trump said: “You could see there was blood coming out of her eyes. Blood coming out of her wherever.”

Trump was promptly dumped from a keynote speaking role on Saturday night in Atlanta at an important gathering of conservative activists put together by the RedState organization. Republican candidates Carly Fiorina, Scott Walker, Lindsey Graham, Rick Perry and George Pataki denounced the comments on Twitter or in statements.

RedState chief Erick Erickson said he disinvited Trump because of his remarks about Kelly on CNN.

The Trump campaign issued a statement clarifying that by “her wherever,” Trump meant Kelly’s nose.

“Mr. Trump made Megyn Kelly look really bad — she was a mess with her anger and totally caught off guard,” the campaign said. Trump said ‘blood was coming out of her eyes and whatever’ meaning nose, but wanted to move on to more important topics. Only a deviant would think anything else.”

Erickson, who invited Kelly to replace Trump at the conference, said he revoked Trump’s invitation because he did not “want someone on stage who gets a hostile question from a lady and his first inclination is to imply it was hormonal.”

A campaign spokeswoman said on Saturday that Trump had fired senior political adviser Roger Stone, the second firing of a senior staffer over the past week. The reason cited was that Stone was using the Trump campaign for his own personal publicity. Stone denied being fired, saying he resigned over the direction of Trump’s campaign.

Trump also took to Twitter on Saturday to renounce politically correct attitudes, as he had done at the debate.

“So many ‘politically correct’ fools in our country,” he wrote. “We have to all get back to work and stop wasting time and energy on nonsense!”

Rival candidates, however, hammered on their doubts that Trump was ready to represent the Republican Party in a presidential run.

“Enough already with Mr. Trump,” said Graham, a senator from South Carolina. “As a party, we are better to risk losing without Donald Trump than trying to win with him.”

He added: “Due to Donald Trump’s unrelenting and offensive attack on Megyn Kelly and others, we are at a crossroads with Mr. Trump.”

Without mentioning Trump’s name, Jeb Bush made reference to him when he spoke to RedState. Bush, former governor of Florida, said the tough questions at the debate were nothing compared to the challenges the next president will face.

“You think that’s tough? How about dealing with (Russian President Vladimir) Putin? How about dealing with the challenges that exist in our country? This is nothing,” he said.

Erickson read aloud some of the emails he had been getting from Trump supporters to protest his move, saying it appeared the Trump campaign had made his email address available to them.

In some of the emails, according to Erickson, the writers used a racial epithet to refer to President Barack Obama and made other inflammatory comments.

“I’ve got to tell you guys, I made the right decision,” said Erickson. “These are the people I don’t ever want at a RedState event.”