If Rick Santorum wants to prove that his near-victory in Iowa wasn't a fluke, then South Carolina is the state where he can try to give Mitt Romney another run for his money.

Evangelical voters were key to Santorum's success in Iowa, and the same will probably be true, if not more so, in South Carolina Jan. 21. While leaders in the evangelical community in South Carolina have made clear that Santorum has grabbed their attention, they have cautioned that those conservative voters are still making up their minds, particularly among him, Newt Gingrich and Rick Perry.

"A lot of people are really, really interested in Santorum than they've ever been because of what happened," said Hal Stevenson, a board member of the Palmetto Family, a conservative group in the state. "I think it's like night and day."

The economy remains voters' top concern pretty much everywhere, and South Carolina is no exception. But underneath, religious voters have no plans to abandon their values in choosing a candidate, according to pastors at a handful of medium and large evangelical churches.

Those Republicans are the voters whom Romney has had trouble converting. Given his history on gay rights and abortion, Romney, a Mormon, isn't as obvious a choice for many evangelicals as are the other three conservatives. Politically, family and religious leaders acknowledge that Romney could emerge as the victor in South Carolina if the primary is a rerun of 2008's contest, when the more centrist Sen. John McCain won as conservatives split their vote among other candidates.

"I've heard one member of my congregation explain it like this: 'I'm tired of voting for the least of several evils,'" said the pastor of a 300-member evangelical Lutheran church, who requested anonymity so he could speak candidly.

Describing Romney, the pastor explained the front-runner's hurdle in South Carolina: "I think the seed of the trouble is essentially in the fact that people in my congregation think he's more moderate than they are, and they don't want to see big government policies, you know, continue."

The latest polls show that Romney does indeed stand to win the South Carolina primary, as long as his conservative rivals stay in the game. In a CNN/TIME/ORC poll last week, Romney held a commanding lead with 37 percent of the vote. Santorum was in second, but with 19 percent, and Newt Gingrich was just behind him, with 18 percent.

All signs point to the South Carolina primary being hard fought. Restore Our Future, a so-called super PAC that supports Romney, is spending $2.3 million on ads in the state; and Winning Our Future, a super PAC that backs Gingrich, plans to spend $3.4 million on ads. The Romney PAC has already started linking Gingrich to abortions in an effort to sway religious voters.

Prominent evangelicals met in Texas after the Iowa caucuses to try to settle on a conservative candidate to support, fearing that Romney would benefit from a fractured split. Neither Santorum nor Gingrich are likely to drop out of the race before Jan. 21, though; Santorum is trying to ride his wave from the Iowa caucuses as far as it will take him, and Gingrich told ABC News Monday that South Carolina is "my must-win state."

Santorum was propelled in Iowa in part by an endorsement from Bob Vander Plaats, an influential Christian leader, who told ABC News last week that he has been making a flurry of calls to South Carolina in an effort to rally like-minded "pro-family" leaders behind the former Pennsylvania senator.

Some pastors said that while they try to keep politics out of their sermons, conversations about the Republican primary abound in their communities more so than in previous years.

Dan Mathewson, a religion professor at Wofford College who has observed the evangelical community in South Carolina for years, said that while Republican voters might normally seek to coalesce around a winning candidate in the primary, evangelicals this year are struggling to find a natural fit. He noted that Santorum, a Catholic, has expressed values that resonate with evangelicals, and that the community has shown that it's suspicious of Romney's beliefs.

"Our church will be extremely involved in the primaries, no doubt," said Ed Carney, the pastor of Riverland Hills Baptist Church, in Columbia, which has about 4,000 members. "From a political standpoint, we'd prefer there be more jobs, and, I think, that's going to be a major emphasis this year."

Brad Atkins, the president of the South Carolina Baptist Convention, stressed that many evangelicals consider issues such as abortion "major" concerns, and, without naming Romney, said that candidates who have murky histories on positions like that will have trouble persuading religious voters that they're sincere.

"There was a sense early in our nation's history that we were one nation under God," Atkins said. "Sadly, the older our country has gotten, the more we've gotten away from those core beliefs."