To participate in the first Republican presidential debate, scheduled for Aug. 23, candidates must meet challenging new criteria, including having at least 40,000 donors and voter support of at least 1% in three approved polls. But the requirement causing the most consternation is a pledge to support the eventual nominee.

The candidates will be sent the pledge only after meeting the other qualifications and will have until 48 hours before the debate to meet those criteria.

Here’s what they’ve said:

Donald Trump

Unclear. The former president has not said whether he will sign the pledge.

In February, he refused to commit to supporting the eventual nominee, telling conservative radio host Hugh Hewitt, “It would have to depend on who the nominee was.” But that was before the Republican National Committee made the pledge a debate requirement.

Even if he signs, it is unlikely to mean much. He signed the same pledge in 2015 and then reneged on it.

Ron DeSantis

Unclear. Asked last month whether he would support Trump in a general election, the Florida governor didn’t give a straight answer.

DeSantis vaguely indicated he might make the pledge, saying, “You respect the process, and you respect the people’s decisions.” But he made no commitment.

Chris Christie

Mixed messages. The former New Jersey governor has suggested he will sign the pledge: “I will do what I need to do to be up on that stage,” he told CNN.

“I’m going to take the pledge just as seriously as Donald Trump took it in 2016,” he said, adding that he considered it “useless” and had told the RNC as much.

Nikki Haley

Yes. The former South Carolina governor and former United Nations ambassador has committed to signing the pledge.

“Absolutely irresponsible that Trump, DeSantis and others won’t commit 100% to supporting the Republican nominee,” she wrote on Twitter. “There’s no room for personal vendettas in this battle to save our country.”

Mike Pence

Mixed messages. The former vice president initially seemed to commit during a CNN town hall event, saying, “I’ve always supported the Republican nominee for president in the United States, and I’ll support the Republican nominee in 2024.”

But he struggled to reconcile that with his assertion that “anyone who puts themselves above the Constitution,” as he says Trump did, “should never be president.”

Will Hurd

No. The former U.S. representative from Texas is the only candidate who has ruled out signing the pledge.

“I can’t lie to get access to a microphone,” he told CNN, adding: “I’m not going to support Donald Trump. I recognize the impact that it has on my ability to get access to the debate stage, but I can’t lie.”

Vivek Ramaswamy

Mixed messages. The entrepreneur has waffled on the pledge.

In February, he said he would make it. But last month, he gave a caveat: “If the other candidates in this race make that pledge, I will stand by and be willing to,” he told Fox News, adding, “I’m ready to play ball, but I require the other candidates to play ball as well.”

Tim Scott

Yes. The U.S. senator from South Carolina has indicated that he will sign.

“All Republican candidates would be better than any Democrat candidate,” he told Fox News, while saying he was confident he would win the nomination.