Rick Santorum is hoping the endorsement of a major evangelical group will help put him over the top next weekend in the crucial South Carolina primary.  On the third ballot of voting, the leaders of the Family Research Council endorsed Santorum in a vote in which he bested Newt Gingrich by an 85 to 29 vote. Conservative Christians are hoping their backing will send a signal to South Carolinians that those seeking an alternative to frontrunner Mitt Romney should choose Santorum. But with the polls in the state still showing the former Pennsylvania senator lagging behind Gingrich and with both trailing Romney, it’s far from clear this will be enough to enable him to duplicate his near-win in Iowa.

The problem for Santorum and his evangelical fans is that Gingrich’s well-financed effort in South Carolina has put him within range of beating Romney himself. The three most recent polls showed Gingrich trailing Romney by two to seven percentage points and Santorum in third some 9 to 15 points out of first. This replicates the same dynamic that has thrust the relatively moderate Romney into a commanding position in the GOP presidential race. So long as conservatives are splitting their votes between Gingrich and Santorum with Rick Perry far behind them with five or six percent of the vote, Romney may well cruise to another victory in a multi-candidate battle.

Had one or two of this conservative trio dropped out after Santorum ran ahead of them in Iowa, that probably would have set him up for a possible win in South Carolina, another state where evangelicals could determine the outcome. But with Gingrich getting a major infusion of cash from big donors in the last two weeks and Perry determined to stick in the race no matter how poor his prospects, it’s difficult to see how Santorum can win. Since a Santorum surge in the last few days in South Carolina will probably come at the expense of Gingrich that may just make it all the more certain Romney comes in first again.

Indeed, the only scenario that could give Santorum a win in South Carolina would involve a collapse by Gingrich. Given the negative reception the former speaker’s attacks on Romney’s business career have received, that’s not out of the question. Santorum’s refusal to engage in Bain-bashing has enhanced his reputation for seriousness while his refusal to pull his punches on issues like abortion or gay marriage have endeared him to evangelicals. But given the major resources Gingrich has put into the state and his current position within striking distance of Romney, it’s going to be tough for Santorum to vault over him as he did in Iowa.

It could be that both Santorum and Gingrich are hoping the third place finisher in South Carolina will drop out after next week along with Perry, leaving just one conservative in the race after that. With 47 states left to vote that would theoretically make it possible for the last “non-Romney” left standing to overtake the frontrunner. But with Romney holding a big lead in Florida, which will be the next primary and with just as good prospects in the states that vote after that, a sweep of Iowa, New Hampshire and South Carolina will solidify the impression that his nomination is inevitable.

With both Gingrich and Santorum hoping to score in the two debates to be held in South Carolina this week, there may yet be enough time for one or the other to emerge as the leading conservative in the race. But barring a collapse by either, it’s difficult to see how their intense competition for conservatives will do anything but aid Romney.