Sen. Rick Santorum, left, and former Massachusetts Gov. Mitt Romney spar during a debate. (Associated Press)

No presidential candidates seem to be calling it quits in the GOP primary and caucus battle, except for Jon Huntsman who announced his resignation Sunday. Frontrunner Mitt Romney followed by Rick Santorum, Ron Paul, Rick Perry and Newt Gingrich all believe that they can still secure the Republican presidential nomination for 2012.

After winning the Iowa caucus by eight votes, Romney went on to win the New Hampshire primary by more than 15 percent. But, within GOP circles Romney is seen as a second option if a better candidate emerges in the race.

Rick Santorum, who placed second in the Iowa caucus, just received a new endorsement from a group of influential family and religious leaders. As a social conservative, Santorum has great appeal within the Christian Right and other evangelical groups because of his views on gay marriage and abortion.

“We need to get this eventually down to a conservative alternative to Mitt Romney,” Santorum said on Fox News Sunday.

Other candidates have attacked Romney’s record as the governor of Massachusetts. Romney has changed his views on state rights, gay marriage and abortion within the last decade.

“I voted from Romney in the New Hampshire primary because I thought he believed in some abortion rights,” said an angry voter on NPR. “But, then I realized he doesn’t anymore.”

Rivals, especially Newt Gingrich, have started to attack Romney’s business record and upper class upbringing. Romney’s time at Bain Capital, a private equity group, could be damaging because a Super PAC in favor of Gingrich has labeled him as a job and company destroyer.

Romney touts that he helped create more than 100,000 jobs at Bain Capital. Organizations like the Washington Post have refuted this number.

But, candidates like Gingrich think that Romney’s overall record will hurt him the most.”I think it’s very hard for him to differentiate RomneyCare from ObamaCare. It’s very hard to differentiate appointing liberal judges which he did when he was the governor of Massachusetts,” Gingrich said to Florida supporters.

“I mean, these are things that are going to come up and I think for the conservative movement it makes it more difficult frankly.”

Members of the GOP are concerned that Gingrich and Santorum are doing the work for President Barack Obama.

But, Gingrich believes that it’s fair to raise questions about the frontrunner in the primary process to avoid problems in the actual presidential race.

“Gingrich is trying to…cast in the minds of the viewing public the idea that he is the ideal debater to go up against President Obama,” said Ben Voth, chairman of the communications studies division, in an interview with USA Today.

As each candidate looks forward to the South Carolina primary, which could be a final effort from multiple campaigns, Mitt Romney looks to become the GOP favorite after South Carolina.