Sen. Jim DeMint (R-S.C.) said it would be a "dealbreaker" for Jon Huntsman or any other Republican presidential candidate not to sign a new balanced-budget pledge behind which DeMint has thrown his political weight.
DeMint is demanding that Republican presidential candidates sign a "Cut, Cap and Balance" pledge drafted by a coalition of conservative groups in order to win his endorsement in 2012, a coveted prize for candidates looking to appeal to conservative primary voters.
But other Republican candidates have been more cautious about signing on to this pledge or any other of the litany of vows conservative groups have demanded of the 2012 field. That might cost them with DeMint, but other Republicans on Capitol Hill, including backers of this latest pledge, are willing to afford the candidates more leeway.
Paul said he wouldn't demand that his competitors for the nomination sign this new pledge, which calls for spending cuts, enforceable spending caps and congressional passage of a balanced-budget amendment in exchange for an agreement for raising the debt limit.
"That's their business," he said.
"I think each one has to make a decision about what's best for their campaign, the party and the country," said Sen. Lindsey Graham (R-S.C.), who added that he thought it would be to the candidates' advantage to support a balanced-budget amendment. "I'm not here telling people what to do, I'm here telling people what I think we need to do."
The developing litmus tests could pose a difficulty for the candidates. On one hand, many of them are looking to build traction with primary voters, and backing these types of pledges is a good way to build support — or, at a minimum, avoid the ire of their party's base.
On the other, Democrats could use some of the pledges against the Republicans who sign them, especially whoever wins the nomination. Just as Democrats have badgered GOP candidates to endorse the House Republican budget, they would seize on less mainstream elements of these pledges.
Sen. Orrin Hatch (R-Utah), a supporter of former Massachusetts Gov. Mitt Romney (R) and a backer of the pledge, said he wouldn't urge Romney to add his name to the list.
"A pledge is a very good thing in some ways. But I know some on our side aren't signing it not because they don't agree with it, but because they're tired of everybody coming up with special pledges," Hatch said. "They feel like if they sign one, they'll have to sign a whole bunch of others. So they draw a line, and I think that's a legitimate point."
If Romney and the other members of the GOP field support the idea behind the pledge, "that's good enough for me," said Hatch.
Indeed, some candidates have sworn off pledges altogether. Huntsman, the former Utah governor and former ambassador to China, said Wednesday that he wouldn't sign an anti-abortion-rights pledge by the Susan B. Anthony List or the longstanding "Taxpayer Protection Pledge" backed by antitax activist Grover Norquist.
Expressing support for the ideas behind the "Cut, Cap and Balance" pledge but refusing to sign it is "not enough," DeMint said. As to Huntsman's refusal to sign all pledges?
"It's a dealbreaker," said the conservative stalwart.
Sen. Mike Lee (R-Utah), another Tea Party darling, was less absolute. He said that signing the pledge wasn't mandatory, but candidates, at a bare minimum, had to at least commit to passing a balanced-budget amendment before agreeing to raise the debt ceiling.
"I won't support any presidential candidate who won't commit to these things. Now, whether they choose to sign it in the form of this pledge or not is up to them," he said. "What I'm saying is it's not enough to just say, 'I'm supportive of the amendment.' He needs to say that there are certain thresholds that he would require to have been cleared before raising the debt limit."
Updated 9:17 a.m.