Former Pennsylvania senator Rick Santorum’s near-victory in Tuesday Iowa caucuses have catapulted him into contention in the 2012 Republican presidential primary race.

Republican presidential candidate, former Pennsylvania Sen. Rick Santorum holds up a twenty-dollar bill as he speaks at a campaign town hall in Northfield, N.H., Thursday, Jan. 5, 2012. (AP Photo/Elise Amendola)

Asked which candidate quality mattered most to them in deciding whom to support, 31 percent of Iowa Republicans on Tuesday said an ability to defeat President Obama was the most important — the highest percentage of any candidate attribute listed in the exit poll.

Of that group, nearly half — 48 percent — voted for former Massachusetts governor Mitt Romney while 20 percent chose former former House Speaker Newt Gingrich. Santorum received just 9 percent among that group despite winning 25 percent of the overall caucus vote.

That’s a problem that Santorum needs to find a way to solve — and quickly. You simply cannot win a nomination where the biggest voting concern for people is beating the incumbent if they don’t think you can, well, beat the incumbent.

Santorum and his team, to their credit, are obviously aware of their “beat Obama” problem. At a town hall in New Hampshire on Wednesday night, he urged the crowd not to “settle for someone who can win, but then can’t do, won’t do and has no track record of doing the big things that are necessary.”

What Santorum is trying to do is cast the race not as a decision over which candidate is the best able to beat Obama but rather over which candidate is more committed to the conservative cause — arguing that electability is a chimera created by the news media.

“Don’t buy the media hype,” he said in New Hampshire. “Don’t buy the lie that you have to be a moderate to be able to win the election.”

A primary fight that revolves around the question of who is the more dedicated conservative is a much more favorable one for Santorum, according to Iowa exit polling.

One in four Iowa caucus-goers said that a candidate being a “true conservative” was the most important quality in deciding their vote; Santorum took 36 percent of those voters while Romney took one percent. (That is not a typo. ONE percent.)

But, Santorum’s ability to consolidate voters who value a “true conservative” is badly hamstrung by the candidacy of Texas Rep. Ron Paul who took 37 percent among that group in Iowa. Paul has shown no signs of even beginning to reconsider his candidacy and it’s hard to imagine him doing so before Florida votes on Jan. 31.

Given that dynamic, Santorum has to find a way to reduce — if not totally eliminate — Romney’s current edge on the electability question.

The simplest way to do that is to win a primary. With Romney holding strong in New Hampshire heading into next Tuesday’s primary, however, Santorum’s best and probably last chance to claim an early state victory is in South Carolina on Jan. 21.

This much is indisputable: If Romney runs away with voters who value electability over all else, he wins the nomination. Fact.