Republican presidential front-runner Mitt Romney appeared Thursday to have successfully blunted attacks on his work at Bain Capital, with still more conservatives coming to his defense, his rivals backing down and voters at campaign stops in South Carolina saying they disapproved of the critique.

But several Republicans said Romney still faces the challenge of persuading blue-collar voters in this recession-hit state that his stewardship of Bain — and the casualties in jobs and factories sometimes left in its wake — was ultimately good for the economy.

The debate over Romney’s business record may be an early test of what is all but certain to become a general-election debate if the former Massachusetts governor wins the GOP nomination.

If the issue picks up steam before the Jan. 21 Republican primary here, it could indicate that Romney would have a stiff challenge ahead persuading voters that his business record uniquely qualifies him to remake a broken government. If Romney is able to beat back the matter, it could suggest that Democrats will have to find another line of attack.

Republican voters at campaign events for Romney and other candidates Thursday said they were unmoved by the arguments against Romney’s time at Bain, a venture capital company that several of Romney’s rivals have blamed for bankrupting companies and laying off thousands of workers. Most damning has been an ad campaign paid for by a group backing Newt Gingrich, featuring interviews with workers claiming to have been laid off by Bain.

“It’s outrageous,” said David Hull, 46, a Daniel Island Republican who attended a rally with Jon Huntsman Jr., the former Utah governor. “The corporate world is totally different from the political world. You have no idea what it takes to save some companies, reduce others. They have to make tough decisions. This is capitalism. We can’t save everybody’s job.”

At a stop along a street in downtown Summerville, S.C., voter Barbara Schimp, a supporter of Texas Gov. Rick Perry, shook Perry’s hand and urged him to “stick to your own story” and stop the attacks on Romney, which she offered, are “coming across as anti-business.”

“Its not anti-business,” replied Perry.

“It just comes across sounding like it,” Schimp said. “Stick to your story, sir, it’s a good story.”

On Wednesday, Perry called Romney a “vulture capitalist” — a phrase that he did not repeat on Thursday.

Romney’s rivals seemed to vacillate between continuing to criticize Romney over Bain and easing up in the face of growing pressure to do so. Gingrich, whose critiques have been the harshest of any, rarely mentioned Romney by name Thursday, sticking instead to a more general “big guy vs. little guy” theme.

Huntsman aimed his attack Thursday on a line Romney uttered Monday about firing people, rather than directly hitting him over Bain. “When you have a candidate who talks about enjoyment of firing people, that makes you pretty much unelectable,” he said.

Several Republican strategists said the verdict is still not in on how damaging the Bain narrative will be for Romney, whose wins in New Hampshire and Iowa earlier this month have cemented his position as the front-runner of the Republican field.

“As long as these attacks continue, they threaten to remake the Romney narrative as one that focuses on him as a corporate raider, which isn’t accurate, but resonates with voters,” said a longtime Republican operative who advises corporations on political strategy. Noting that the attacks are likely to continue into the fall, the operative added that Romney has “got to get to a place where he feels comfortable enough in saying that being a turnaround guy causes some short-term pain, but in the end it’s better.”

It could be particularly difficult to counter the emotional bent of the pro-Gingrich ads, in which a man says, “Mitt Romney and them guys — they don’t care about us,” and a woman says, “Mitt Romney, I feel, is the man that destroyed us.”

Romney didn’t hesitate to defend his Bain record at a motorcycle shop near Greenville early Thursday. After a campaign rally in a garage filled with customized bikes, Romney conceded that some of the businesses his company took over shed jobs under his watch. But many more added jobs, with a net addition of more than 100,000 jobs, he claimed.

“Any time a job is lost it’s a tragedy,” Romney said. “For the family, for the individual that loses a job, it’s devastating. And every time that we invested in the business it was to try and encourage that business to have ongoing life.”

But, Romney said: “The reality is in the private sector . . . there’s some businesses that have to be cut back in order to survive and try to make them stronger. And sometimes you’re successful at that and sometimes you’re not.”

The topic of Bain Capital has exposed a delicate tension within the Republican Party, which has long defended free enterprise while also trying to capture the hearts of blue-collar workers — and court tea party activists angry at companies that lobby for government aid.

Many tea party activists in South Carolina are mobilizing against Romney, and several said in interviews this week they view the Bain attacks as legitimate.

Keith Tripp, 65, a residential construction contractor who is active in a Laurens, S.C., tea party group, recoiled at the assertions from Romney and his allies that questioning Bain was an assault on capitalism.

“The fact that there are abuses in capitalism, and you point out abuses in capitalism, does that make you anti-capitalist?” asked Tripp, whose tea party group has endorsed Gingrich. “For instance, have you heard Romney talk about crony capitalism? What’s the difference in that and saying that somebody as a capitalist has not acted properly?”

Others say the attacks serve as a less-than-subtle reminder that Romney, despite often wearing jeans and open-collared shirts on the campaign trail, as he did Thursday, is a wealthy executive type who shares more in common with mega-corporations than with Main Street business owners and workers.

“I think he’s in another world,” said Joe Dugan, a Myrtle Beach activist and Gingrich backer who is organizing a tea party convention this weekend featuring appearances by Gingrich and Santorum. Dugan said Bain is fair game. “With all his million-dollar homes, he doesn’t understand the everyday American.”

A number of conservative leaders have come to Romney’s defense, including Sen. Jim DeMint (R-S.C.) and Tim Phillips, who leads the tea-party-friendly Americans for Prosperity. On Thursday, a former Perry donor and former South Carolina GOP chairman, Barry Wynn, switched teams and endorsed Romney — in part over the Bain issue.

Staff writers Nia-Malika Henderson, Steve Hendrix, Stephanie McCrummen and Sandhya Somashekhar contributed to this report.