Santorum accuses Romney of "dirty, dishonest politics"

UPDATED 3:30 p.m. ET

MT. PLEASANT, S.C. -- Republican presidential candidate Rick Santorum launched an aggressive line of attack against front-runner Mitt Romney on the campaign trail this morning, calling his tactics "dirty, dishonest politics."

"I'm stunned that Mitt Romney does not have the ability to discern something that is blatantly false," Santorum said at a press conference this morning, criticizing an ad being run in South Carolina by Restore Our Future, a super PAC supporting Romney. "This is a huge character issue on Mitt Romney's part, he needs to step up and do the right thing and quit playing dirty politics. He's playing dirty dishonest politics."

It was a continuation of Santorum's edgy questioning of Romney at a candidates' debate Monday night. In both instances Santorum claimed that the ad misrepresented his record on the issue of felons recouping their full rights after they paid their debt to society.

Santorum has said that the ads are misleading. Romney has said repeatedly he has no control over the super PAC, which under law is not allowed to coordinate with a candidate's campaigns, but that the ads seem accurate to him.

Santorum launched his own attack ad in South Carolina today. Called "Easy Answer," it compares Mitt Romney to President Obama. "I don't consider that a negative ad. I just consider that to be an ad that just tells the truth," he said at this press conference, held aboard the U.S.S. Yorktown where he was scheduled to hold a town hall meeting on national security.

Santorum also called foul play on robocalls being made around the state that he said feature his 2008 endorsement of Romney the last time Romney ran for president.

"We have Gov. Romney who's timid and isn't what the country needs, and you have Newt, who's bold but all over the place, attacking capitalism, supporting capitalism; against global warming, for global warming," Santorum said. "We need someone who's bold and consistent. And that's why I believe we're the alternative."

He also said, "I would make the argument that Speaker Gingrich is not nearly as conservative as I am on most of the issues."