Former President Donald J. Trump said on Wednesday that he was unwilling to meet one of the requirements to participate in the first Republican presidential debate, refusing to sign a pledge to support the eventual nominee.
“I wouldn’t sign the pledge,” he said in an interview with the conservative outlet Newsmax. “Why would I sign a pledge? There are people on there that I wouldn’t have.”
The decision would seem to rule out the possibility of him being at the debate on Aug. 23, yet he also said that he would announce next week whether he planned to take part.
Asked for comment on Thursday, the Republican National Committee, which sets the rules, referred to past interviews in which its chairwoman, Ronna McDaniel, has defended the pledge and said the committee will hold everyone to it.
“The rules aren’t changing,” she said on CNN last month. “We’ve been very vocal with them.”
In the Newsmax interview, Mr. Trump said, “I can name three or four people that I wouldn’t support for president,” without naming them. “So right there, there’s a problem right there.”
Mr. Trump also said that he wasn’t convinced it was worth it for him to debate given how far ahead he is in the primary, and that he wasn’t worried that the debate would change his standing. A recent New York Times/Siena College poll showed him leading the field by an enormous margin, more than 35 percentage points ahead of his nearest competitor, Gov. Ron DeSantis of Florida.
“If you have a 20-stroke lead going into the 18th hole, you tend not to be that worried,” he said at his golf course in Bedminster, N.J., on Thursday, as Cameron Smith, the 2022 British Open winner, stood a few feet away.
Some other Republicans criticized Mr. Trump on Thursday for his refusal to commit to supporting a nominee other than himself. “Every Republican running for President would be better than Joe Biden,” Gov. Brian Kemp of Georgia said on Twitter. “Any candidate who does not commit to supporting the eventual nominee is putting themselves ahead of the future of our country.”
At least two other candidates have already signed the pledge: Mr. DeSantis and Nikki Haley, the former governor of South Carolina and former United Nations ambassador under Mr. Trump. “Alright fellas, your turn,” she wrote on Twitter on Thursday.
Mr. Trump’s vacillation over the pledge is not new; he objected to signing the same loyalty pledge during his first campaign eight years ago. He ultimately did, but then took it back.
That history underscores that the pledge is, in practice, unenforceable. Party leaders can refuse to let a candidate debate for not signing, but they can’t force someone who does sign to actually support another nominee next year.
One of Mr. Trump’s opponents, former Gov. Chris Christie of New Jersey, has said that he will sign the pledge, but that he would not support Mr. Trump if he is the eventual nominee: “I’m going to take the pledge just as seriously as Donald Trump took it in 2016,” he told CNN.
Another opponent, former Gov. Asa Hutchinson of Arkansas, has suggested that — if he otherwise qualifies for the debate, which he hasn’t yet — he would sign based on the far-from-safe assumption that Mr. Trump won’t be the nominee and Mr. Hutchinson won’t actually be tested.
Alan Blinder contributed reporting from Bedminster, N.J.