Saturday should be another good day for Rick Santorum, as his strength has been in Southern states. Polls in Louisiana, which is holding its primary, also gave him a double-digit lead over Mitt Romney coming into the weekend.
The Sportsman's Paradise has 46 Republican delegates to send to the party's presidential-nominating convention. But the very helpful Frontloading HQ blog informs us that only 20 of 25 at-large delegates will be doled out based on Saturday's results.
That said, here are four things to watch for as results come in Saturday (polls close at 9 p.m. ET):
Romney's share of the vote — Assuming the polls are right and Santorum gets the plurality of votes, does Romney get at least 25 percent?
The answer to that is central because, according to Louisiana Republican Party rules, to be allocated at-large delegates, a candidate must reach this 25 percent threshold. Some polls have shown Romney within the margin of error of that threshold. If he falls below it, Santorum would get all 20 at-large delegates.
That would be another embarrassing blow to Romney's argument that he is the inevitable candidate because he has the most delegates so far. And it would be another successful battle in Santorum and Newt Gingrich's war to keep Romney from securing enough delegates before the national convention in August.
Evangelical and Catholic voters — Louisiana has a large Catholic population and, interestingly, even though Santorum is Catholic, Romney has consistently done better than his ex-senator rival with those voters during the primary season.
Catholics made up about 31 percent of the voters in the 2008 Louisiana Republican primary, roughly tracking with their percentage in the population. Sen. John McCain easily won a majority of those Catholics. If Romney can do likewise, that could help him get to that 25 percent threshold he needs to meet.
Meanwhile, about 57 percent of voters in the 2008 primary identified themselves in exit polls as evangelicals. These voters have tended to break more for Santorum than Romney, but they form a lower percentage of primary voters in Louisiana than they did in some other Southern states.
Still, it will be important to keep an eye on how these voters split. In Mississippi, for instance, Santorum got 35 percent of these voters, Gingrich got 32 percent and Romney had 29 percent.
If Gingrich, whose support has weakened, does less well with evangelicals and Romney gets some of that support, that could also help him reach the 25 percent threshold and make it a closer race than it looked going into the weekend.
Geography -- Romney has tended to do better with upscale voters in counties with big metropolitan centers, while Santorum's strength is in more rural areas. That trend is expected to hold sway Saturday, too.
If Romney can get his voters to turn out in Louisiana's population centers of New Orleans and Baton Rouge, for instance, they could swamp Santorum's more rural vote and, again, make the race unexpectedly closer than it appeared to be in the days leading up to it.
Late decisions -- Another thing to look for in exit polls would be if voters who decided to vote late, like in the polling place or the day before, voted differently than those voters who made their minds up earlier.
If, for instance, late deciders went more for Santorum, that could suggests that the Etch A Sketch gaffe by one of Romney's top aides played a role and could spell danger for Romney down the road.
Copyright 2012 National Public Radio. To see more, visit http://www.npr.org/.