The Republican primary battle heads back to the South Saturday as Louisiana holds its primary contest.

Recent polling has  Rick Santorum in the lead, but Republican state officials say they don't  discount the possibility of a late surge by Mitt Romney, or a tight three-way race among Santorum, Romney and Newt Gingrich.

Here are five  key points to keep in mind as you watch the  results come in.

No. 1: Forty-six  delegates are at stake. But there's a twist.

Only 20 of them will be doled out  on Saturday night. The remaining 26  delegates will not be allocated until the state convention in June.

No. 2: Louisiana voters are more conservative than Illinois voters.

Mike Huckabee narrowly carried Louisiana in 2008. He received 43 percent of the vote, while John McCain got 42 percent.  Despite the narrowness of the margin, that victory is noteworthy because Louisiana held its primary after Super Tuesday, when  McCain had solidified his stance as the apparent Republican nominee.

In 2008, 44 percent of voters participating in the Republican Louisiana  primary identified themselves as very conservative, according to exit polls. To compare, in last Tuesday's primary contest in Illinois, only 29 percent of voters called themselves very conservative. Romney won Illinois with a double-digit margin: 47 percent to Santorum's 35 percent.

No. 3:  Louisiana's evangelical electorate is  smaller than Mississippi's and Alabama's.

It's tempting to compare Louisiana's voting population to that of nearby Alabama and Mississippi -  two states won by Santorum - but Louisiana's  voters are significantly less evangelical. Exit polls taken at the Mississippi and Alabama primaries showed that 83 percent in Mississippi and 80 percent in Alabama  identified as evangelical. In 2008, exit polls showed that 57 percent of voters in the Louisiana Republican primary identified as evangelical.

No 4: The New Orleans suburbs are Romney areas. The southeastern portion of the state will likely be a Santorum stronghold.

In 2008 McCain finished strong in Louisiana by carrying the populous parishes in and surrounding Baton Rouge and New Orleans. Mike Huckabee essentially won the rest of the state. In 2012, look for Romney's and Santorum's performances to mirror McCain's and Huckabee's.

If turnout is strong in the parishes in and around  New Orleans and Baton Rouge, the capital, it will likely bode well for Romney, Republican Party officials tell ABC News. Turnout in the southeastern part of the state, as well as the north, will likely mean good news for Santorum. The southeastern portion could be a particularly strong area for Santorum, because of the large Catholic population, according to state Republican Party officials  If Gingrich can pull  out a strong performance, it will likely be in  Santorum's region, which would split the vote and help Romney.

No. 5: This primary marks  the end of a busy month, and the beginning of a quieter time on the trail.

After the April 3 primaries  in D.C., Maryland and Wisconsin, prepare for a bit of a lull.