Rick Santorum attacks former pal Newt Gingrich

ROCK HILL, S.C. - With Newt Gingrich breaking out of the pack as the conservative alternative to front-runner Mitt Romney in South Carolina, he came under attack Friday from an old friend and colleague in Congress, former U.S. Sen. Rick Santorum of Pennsylvania.

Santorum had largely avoided political attacks against Gingrich, whom he once considered a political mentor. But on Friday, the glove came off as Santorum took the former House speaker to task for being insufficiently conservative on climate change, free markets and health care.

"Conservative alternatives don't go out and attack the capitalist system as he has done. Conservative alternatives don't promote global warming, don't argue for individual mandates for the federal government on health care," Santorum told reporters before a town hall meeting in Rock Hill.

He also hit Gingrich on his tumultuous career in the House leadership, contrasting it with his own time in the leadership of the Senate.

"When I was in the leadership of the United States Senate, conservatives came to me to get things done in Washington. When Newt was in the leadership in the United States House as speaker, three years into his term, conservatives tried to throw him out," Santorum said. "If you're looking for the conservative alternative, look for the person who has a conservative record."

He added that Gingrich has never run a statewide race or demonstrated his ability to appeal to swing state voters.

His remarks make clear that Santorum increasingly sees Gingrich, rather than Texas Gov. Rick Perry, as the major obstacle in his path to become the conservative alternative to front-runner Romney in the state's upcoming primary on Jan. 21. The former Massachusetts governor is viewed by many conservatives as too moderate and too prone to flip flop on issues, like abortion rights and health care.