Mitt Romney and Jeb Bush might want Republicans to unite behind the Romney banner after his big Illinois win on Tuesday, but Louisiana Republicans have other ideas.  In Rasmussen’s new poll before the state’s closed primary on Saturday, Rick Santorum has a 12-point lead, and by 20 points in a two man race — even though almost three-quarters of the likely voters surveyed think Romney will win the nomination anyway:

Former Pennsylvania Senator Rick Santorum is comfortably ahead in Louisiana with that state’s Republican Primary just two days away.

A new Rasmussen Reports telephone survey of Likely GOP Primary Voters in Louisiana finds Santorum with a 12-point lead over former Massachusetts Governor Mitt Romney – 43% to 31%. Former House Speaker Newt Gingrich who has pinned his hopes on capturing other Southern states beyond South Carolina and his native Georgia runs a distant third with 16% support. Texas Congressman Ron Paul comes in last with five percent (5%). One percent (1%) prefer some other candidate, and five percent (5%) are undecided. (To see survey question wording,click here.)

Highlighting Santorum’s continued strength in states with large numbers of conservative voters, he leads Romney 57% to 37% in a one-on-one matchup in Louisiana.

Santorum’s numbers look solid in the internals, too.  He has almost identical leads among men (42/32) and women (43/30), and leads every age and income demo, although only edging Romney by two among seniors, those earning under $20K, and those earning between $40-60K.  Romney wins “somewhat conservative” and “other” voters by six and eight points respective, but Santorum carries “very conservative” by 26 points, 49/23.  While Romney has been winning the Catholic vote, he loses it in Louisiana by ten points, and evangelicals by 28 points, as one might expect.

Newt Gingrich has parked himself in the Pelican State in a last-ditch effort to regain some momentum, but this poll has nothing but bad news for him.  He trails badly with 16% of the vote; Romney beats him almost 2-1 in second place.  He’s viewed favorably by Louisiana Republicans, 68/29, but Santorum’s favorability is 84/14 and Romney’s is 72/27. There isn’t much room for him to get traction against either candidate in front of him, and a poor third-place showing in the South would probably mean the end of his campaign, especially if he can’t win any delegates in Louisiana.  A shutout would end whatever credibility he has left as a candidate even in a delegate-gathering sense.

In fact, this poll suggests that no big surprises will occur on Saturday. With 88% of voters firm in their selection, there isn’t enough voters to change, barring a last-minute gaffe by Santorum.  That will give Santorum a little bit of momentum heading into the ten-day break and allow him to put off calls to concede the race on the grounds of party unity until April at the earliest.  Given that 73% of the respondents expect Romney to get the nomination but only 31% want to vote for him, Santorum has at least some basis for sticking around a little longer.

Update: Stacy McCain says I’m not on drugs for picking up on Gingrich’s troubles, unlike the rest of the media.  I think that assumes facts not in evidence, though (and I’ll never tell).