GREENVILLE, S.C. - After weeks of dancing around their diverse backgrounds, Rick Santorum today attempted to draw a  clear contrast between himself and Mitt Romney, saying his blue collar upbringing makes him a better candidate in crucial swing states than Romney's experience at a private equity firm.

"You want to win this election? Then we've got to go to the states where you win the election and it's Pennsylvania, Ohio, Michigan, Indiana, North Carolina, Missouri, Wisconsin. How do you win elections as a Republican in these states? You do it by getting Reagan Democrats to vote for you," Santorum told a crowd of about 200 before laying into his opponent.

"I respect Mitt Romney's career in business, but the grandson of a coalminer who grew up in public housing in a steel town in Western Pennsylvania and whose policies are oriented toward helping those and whose record is a track record of working in those blue collar communities has a much better chance of winning those states than an executive from Bain Capital," he said.

When Santorum was young he lived in Veteran's Administration housing with his parents. Both of his parents worked for the V.A., his mother as a nurse and his father as a psychologist. He did not live in low income housing, instead living on the grounds because of his parents' careers.

Santorum has refused to criticize Romney for his work at Bain Capital, something both Newt Gingrich and Rick Perry have made an issue of while trying to make gains on the race's frontrunner. Friday in Gaffney, S.C., Santorum said that for him the issue is completely off the table.

"I am not going to be critical of him for practicing free market capitalism in the private equity business. And the reason is because I believe in capitalism, both constructive capitalism and deconstructive capitalism," Santorum said at a campaign stop at a fast food restaurant.

At Tommy's Country Ham House today, the former Pennsylvania senator also jabbed the race's frontrunner for his health care plan in Massachusetts, which was expected to be a central campaign theme but has hardly been pounced on by rivals.

Santorum said it makes Romney unable to take on President Obama in a general election.

"Why would we pick someone who's had a record as a liberal governor of Massachusetts to lead our country at a time we need fundamental change?" he said. "The problem is the person who's leading in the polls in the primary is someone who can't make that case because he passed a bill similar to 'Obamacare' and still says today it was the right thing to do."

"He says it was the right thing for Massachusetts. What do you think Obama is going to do with that? 'Oh, it's right for Massachusetts.' And he's said at times it would be right for the country. He's going to destroy him. That issue will be gone," he said. "The most important issue we have in this election about fundamental freedom and the role of government in your lives we forfeit. Why would we do that?"

He added that "just because" Romney says he will repeal the president's health care plan now, it doesn't mean he will.

"What would make you think the American public would trust him to do it in the future?" Santorum said.

Romney may be ahead in the race for the first in the South primary held next week and Santorum is targeting him, but he rarely contrasts himself with others in the race, including those candidates he is more closely competing with in the polls like Newt Gingrich, although Friday night in Duncan he did criticize the former speaker's immigration stance.

He got in another veiled hit at Romney today when talking about his own socially conservative platform, saying being president is "not just an economic plan."

"We just don't need someone who goes out there and says 'I'm a good manager,'" Santorum said. "We're not running a business here, we're running a moral enterprise that is America."

He implored the audience to vote for him and said Republicans need a candidate who "reflect(s) the values" of people in this region of the Palmetto State, the most conservative part of South Carolina.

"Folks here in the upstate understand faith. They understand families instill faith, and with faith comes a moral understanding of what your obligations are, not just to your God, but to your fellow men," Santorum said. "The less moral we are, the less well behaved we are, the bigger government gets and the less free all of us become.

Santorum planned to travel to Mt. Pleasant later today for more campaign stops before going to the coast tomorrow as he fights to regain the momentum he had when he lost to Romney by only eight votes earlier this month in Iowa.

He came in fifth in the New Hampshire primary, not even cracking double digits, but he has said he hopes the more socially conservative and religious electorate in this state is a better match.