The one word used most often to describe Rick Santorum’s debate performance Wednesday night was this one: Defensive. (Ross D. Franklin/AP)

This is not entirely surprising, given his most recent rise in the polls. After wins in Colorado, Missouri and Minnesota, the former Pennsylvania senator has been seen as a viable threat to Mitt Romney’s frontrunner status, polling ahead of Romney in his home state of Michigan. That brought the claws out Wednesday night—not only from Romney, but from even the likes of Ron Paul, who went so far as to call Santorum “a fake.”

What is surprising is that a candidate most known for being the “conviction candidate” and “so assured of his positions” should find himself playing so much defense. Santorum has used his mantle as the race’s most social conservative to depict himself as the “authentic,” consistent conservative, setting up a contrast between his steadfast principles and Romney’s reputation for shifting positions on issues. He not only thinks Catholic organizations shouldn’t have to pay for birth control; he has called birth control “harmful to women.” He doesn’t just talk up his faith and belief in Christianity; he says he believes “in good and evil” and has said “Satan” is “attacking the great institutions of America.”

While those staunch views and that steady allegiance to his principles may draw many voters toward him—when asked which one word describes him most, Santorum replied “courage”—it can also backfire. Not only does he risk being seen as judgmental and as telling “others how to behave and even what to believe, using his own specific beliefs as an unshakable guide,” but such chiding certainty makes any inconsistencies that do exist that much more glaring, and that much more ripe for defending.

To wit, consider the tortured situation Santorum found himself in Wednesday night as he tried to explain his position on earmarks. In summary, he was for earmarks, as the saying goes, until he was against them. When challenged about his support for President George W. Bush’s education law No Child Left Behind, he did not defend the merits of the law that made him support it before he later regretted doing so. Rather, he said “politics is a team sport, folks,” explaining that sometimes you have to vote for things you don’t like due to the way Washington works. He was even accused of funding Planned Parenthood—anathema to a social conservative—by voting for broader bills, and was booed by the crowd for his response.

Santorum’s “conviction candidate” approach may be winning him more and more votes as the culture wars gain steam in this election season. He may be setting himself up as the viable not-Romney as he collects delegates in state after state. But just as his staunch allegiance to his principles is helping him win fans, it can just as easily have him playing defense. People want to see leaders who firmly believe in their ideals, but when the allegiance to those ideas is taken to an extreme, they have just as much potential to hurt the candidate.

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