Once His Student, Rick Santorum Moves to Give Newt Gingrich Lessons CHARLESTON, S.C. - Late in Thursday night's debate, Newt Gingrich yielded his time to Rick Santorum to address whether Mitt Romney genuinely opposed abortion rights. Most candidates like to hoard screen time for themselves, but Mr. Gingrich knew that Mr. Santorum was as versed and passionate on the subject as anyone. So he decorously deferred to Mr. Santorum, expecting him to dismantle Mr. Romney's record. Mr. Santorum did. But he did not stop there. In an unexpected twist, he went on to use Mr. Gingrich's own time to attack Mr. Gingrich's commitment to the cause. It was a telling moment - one that revealed Mr. Santorum's newfound urgency to undercut Mr. Gingrich. The two are headed for a climactic showdown Saturday in the South Carolina presidential primary. The outcome will most likely shape the course of the nominating contest while it shreds a personal relationship of more than two decades. Mr. Santorum, 53, a former senator of Pennsylvania, and Mr. Gingrich, 68, a former speaker of the House, are competing ferociously for the same pool of conservative and evangelical voters, who make up 60 percent of South Carolina's registered Republicans. Whoever lags behind the other will face intense pressure to drop out in hopes that conservatives can unite and block the more moderate Mr. Romney. But both are digging in and preparing for the next primary, in Florida on Jan. 31. "If they both stay in, they both lose," said Frank Luntz, a Republican pollster who was a longtime adviser to Mr. Gingrich but is a friend of Mr. Santorum and says he is neutral in their standoff. One of them has to go. But they both have the right to stay in. As often happens in primaries, the two rivals are longtime allies. But in this case, one, Mr. Santorum, was a student of the other, and their rivalry seems to have taken on a generational cast. "Essentially, Santorum has the new guard, and Newt has the old guard," said John Brabender, Mr. Santorum's senior media adviser. When he was running for a Congressional seat in Pennsylvania in 1990, Mr. Santorum was one of a generation of young Republicans whom Mr. Gingrich schooled in conservative philosophy and rebel tactics. Mr. Gingrich, with his provocative language, helped train the recruits by recording cassette tapes so they could absorb his advice and worldview. "Newt Gingrich was the guy whose tapes I listened to," Mr. Santorum recalled at an earlier debate, before the two became such rivals. He laid out a vision for conservative governance that I adopted and ran with in a very, very tough Congressional district. They still hold similar political views. They both call for less government and lower taxes and express a reverence for the founding fathers and revulsion toward "elites." "If there's a degree of separation, Rick draws more from the hard-core social conservatives, especially on gay marriage, and Newt draws a little bit more on the economic freedom side of it," said Charlie Gerow, a Republican consultant who is friends with both, but is now Mr. Gingrich's Pennsylvania chairman. "But beyond that," he said, "their philosophy is almost totally the same." Now, with polls suggesting Mr. Gingrich is ahead of Mr. Santorum here, the acolyte has turned on the master. "Newt's a friend, I love him," Mr. Santorum said at the debate here with a pained expression even as he savaged him as having "grandiose" ideas, "incoherent thoughts" and "no discipline." The party, he said, would always be worried "that something's going to pop." He also noted that Mr. Gingrich was forced out of the speakership by his own troops. Mr. Gingrich refrained from lashing back at the debate, though he does so on the campaign trail, dismissing Mr. Santorum as a "junior partner" in the Republican revolution. "Rick played a key role in passing welfare reform, no question," Mr. Gingrich told a crowd, adding quickly, "It wouldn't have happened if I hadn't been speaker." He also says Mr. Santorum is not equipped to manage a national campaign on the scale necessary to beat President Obama or bring true change to Washington. Mr. Gingrich reminds voters that Mr. Santorum lost his Senate re-election bid in 2006 by a crushing 18 percentage points. This infuriates Mr. Santorum because he won more votes than Mr. Gingrich in Iowa (even belatedly winning the state) and in New Hampshire. Allies of both men were surprised by the amount of blood spilled at Thursday's debate but thought the attacks would make little difference to voters. "I think Rick is feeling a little desperate at this point," said Bob Walker, a former representative of Pennsylvania, a senior adviser to Mr. Gingrich. I think he does see a coalescing taking place among conservatives around Newt's candidacy and he's fighting to make himself relevant. It is not clear whether the current rift in the Santorum-Gingrich relationship will be permanent. Some political veterans suggest they could still work together in the future, even after all this. "Go back and look what Hillary Clinton and Barack Obama were saying about each other four years ago in South Carolina," said Stuart Stevens, a top adviser to Mr. Romney. It was just vicious, vicious. That was a campaign that left Bill Clinton in tears. Now, of course, those three may be a team of rivals, but they are a team.