This Saturday, the battle for the GOP presidential nomination heads south for Louisiana's primary, and polls suggest Rick Santorum is in for a "smashing victory." In a Public Policy Polling survey of likely Republican voters, 42 percent chose Santorum, while 28 percent gravitated toward frontrunner Mitt Romney, 18 percent opted for Newt Gingrich, and 8 percent for Ron Paul. How will the results in Louisiana affect the race? Here are four key factors:

1. Can Santorum revive his chances with a landslide victory?
"What Santorum needs, of course, is not just a win in Louisiana, but a big win," says Alexander Burns at Politico. He needs to prove he's the overwhelming favorite of the party's conservative base, and put an exclamation point on the sentence "Romney's shut-out in the Deep South," following the frontrunner's losses in South Carolina, Georgia, Mississippi, and Alabama.

2. Can Romney do well enough to quiet skeptics?
Romney is walking into another defeat, "if past is prologue," says Aaron Blake in The Washington Post. Still, given that Louisiana is "more fertile ground" for Romney than other Deep South states, he might fare surprisingly well. Louisiana is the least rural, "least evangelical and most Catholic Southern state to vote so far," all pluses for Romney. And Georgia native Newt Gingrich could siphon support from his fellow conservative Santorum. If Romney does manage to defy the polls, and even win, says Ben Jacobs at The Daily Beast, he'll "show that he has appeal in the Republican heart of the country" and "avoid the prospect of a humiliating shutout."

3. Is this Gingrich's last stand?
If Gingrich can't "do well in Louisiana, then it's pretty much finished," Ed Chervenak, a University of New Orleans political scientist, tells USA Today. Romney, a former Massachusetts governor, has struggled with the perception that he's not conservative enough for the South. So if Gingrich can't pick up more delegates than Romney on what's supposed to be his home turf, it's a clear sign that Gingrich's campaign is "going nowhere."

4. Who gets the state's delegates?
Even a double-digit victory might not help Santorum's chances much, says David Weigel at Slate. Only 20 of Louisiana's 46 delegates are up for grabs on Saturday — the rest are awarded at a June convention. The ones decided on Saturday will be divvied up among all candidates who get 25 percent or more of the statewide vote. If the results are in line with the polls, Santorum will get nine delegates, Romney will get six, and five will remain uncommitted. Santorum needs for Romney to fall short, and land "in a big cluster" underneath the 25-percent threshold. "Failing that, [Santorum] doesn't take much out of Louisiana."