Mitt Romney's GOP presidential rivals have been trying for days to brand the frontrunner as a heartless corporate raider who, as co-founder of Bain Capital in the 1980s, fired people in droves to make quick profits while restructuring troubled companies. As the battle for votes heats up in South Carolina, set to host its Jan. 21 primary, Romney's campaign is trying to counter a barrage of negative ads, including radio and TV spots by a Gingrich-friendly super PAC that's purchased $3.4 million of airtime. Those ads will feature excerpts from a scathing documentary that says Bain damaged the lives of ordinary workers. Here, three arguments Romney will deploy to transform his record at Bain from a liability to an asset:

1. Romney's GOP rivals sound like President Obama
Romney wants to frame the 2012 election as a contest with President Obama over the economy, says Mike Dorning at Bloomberg. But now, Romney's Republican rivals are hitting him with many of the same arguments Obama has used (and will use). Texas Gov. Rick Perry accuses Romney of "vulture" capitalism, and Gingrich says Mitt exploited others' misfortune for "enormous personal gain." In a new ad, Romney uses the issue to link his rivals to the Right's nemesis. "We expected the Obama administration to put free markets on trial," a narrator says, "but as The Wall Street Journal said, 'Mr. Romney's GOP opponents are embarrassing themselves by taking the Obama line.'" (Watch the video below.)

2. Bain saved companies — and jobs
In New Hampshire, Romney countered criticism of his years as a venture capitalist by saying that when he ran Bain in the 1980s, it helped companies like Staples, Sports Authority, and Steel Dynamics create thousands of jobs. Now, the campaign is spending more than $400,000 to air a 30-second spot touting Romney's role creating or saving tens of thousands of jobs. "For every scare story that they try to present related to the governor's experience in the private sector and free enterprise," Romney adviser Kevin Madden tells Politico, "we can point to a whole host of successful enterprises that have resulted in job creation and wealth and prosperity."

3. Americans who are critical of Wall Street are just jealous
The GOP frontrunner spelled out another line of attack in an interview with NBC's Matt Lauer, when he said that the wave of Occupy Wall Street anger at the wealthiest Americans is fueled by jealousy, not a sense of fairness. "I think it's about envy," Romney told NBC. "I think it's about class warfare." And Romney has criticized Obama for perpetuating such tensions as a "leader who divides us with the bitter politics of envy." Gingrich pounced on that statement. "If anybody asks a question about (Romney's) record, he hides behind an entire framework and to question the facts is to be anti-capitalist," Gingrich said. "That is nonsense — baloney."

Sources: Bloomberg, Business Insider, Huffington Post, New York Times, PoliticoWashington Post