NASHUA, N.H. -- Mitt Romney's Republican rivals accused him Monday of exaggerating his successes and coldly laying off thousands of workers while heading a profitable venture capital firm, an effort to turn the presidential front-runner's biggest asset into a liability.
The heightened focus on the firm Bain Capital threatens to slow Romney's cruise-control campaign because it goes to the heart of his No. 1 appeal to voters: the claim that he knows far more than President Barack Obama about creating jobs.
Romney's takeover-and- restructuring firm "apparently looted the companies, left people unemployed and walked off with millions of dollars," former House Speaker Newt Gingrich said on NBC's "Today" show.
A group friendly to Gingrich is preparing to air TV ads of laid-off workers denouncing Romney, who interrupted his time at Bain to serve as Massachusetts governor.
Texas Gov. Rick Perry joined in. He cited South Carolina companies that Bain bought and downsized, and he practically dared Romney to ask for voters' support there in the name of easing economic pain.
"He caused it," Perry said in Anderson, S.C.
Romney points to thousands of jobs created at companies that Bain bought, invested in or restructured.
He remained favored to win today's New Hampshire primary. But his rivals might improve their hopes of halting his momentum in South Carolina's Jan. 21 primary if they can persuade voters that his jobs legacy is not what he claims.
Thanks to millions of dollars from a Las Vegas casino owner who supports Gingrich, TV ads in South Carolina will try to do just that. They show angry victims of layoffs from Bain-controlled companies, according to excerpts shown to reporters.
On the campaign trail, Romney rarely mentions his four years as governor unless asked. But he constantly touts his time in the private sector, asking voters to trust his instincts and experience in creating jobs.
The claims rely on Romney's career at Bain, a Boston-based private equity firm that poured investors' money, and Bain executives' expertise, into more than 100 companies in the 1980s and '90s. Some of the companies thrived and expanded. Some took on unsustainable debt and went bankrupt. Some became leaner or were broken into various parts, shedding jobs and improving profits.
In a recent debate, Romney repeated his claim that the Bain-run companies netted a total increase of 100,000 jobs.
Studies by The Associated Press and other news organizations conclude that the claim doesn't withstand scrutiny. That alone, however, hardly suggests Romney was an unsuccessful business executive. He became wealthy, a hero to many entrepreneurs and leader of the 2002 Winter Olympics.
The 100,000 jobs claim comes from activities at only three companies, all of them successes: Staples, Domino's and Sports Authority. However, it counts many jobs that were created after Romney left Bain in 1999. And it ignores job losses at many other firms that Bain invested in or took over.