We just got an e-mail from John Diez, pollster/demographer extraordinaire, with some interesting information…

Magellan Strategies BR today released the survey results of an autodial survey of 2,018 likely Republican Primary voters in Louisiana. The survey was conducted March 19^th, 2012 and has a margin of error of +/-2.18%. This survey was not paid for by any campaign or political organization.

The survey finds former U.S. Senator Rick Santorum leading his closest opponent by 13 points (Santorum 37%/Romney 24%/Gingrich 21%/Paul 3%/others 9%/undecided 6%). With only 5 days until the primary, Santorum’s strong image (72% favorable/20% unfavorable) and relatively few undecided voters (6%) puts him in a strong position to win a plurality in the Louisiana GOP Primary. Santorum leads among both men and women, among all age groups and in all 6 congressional districts.

Though currently running second, Romney’s struggling image could potentially hinder any growth potential. Currently, Romney’s image is 49% favorable to 41% unfavorable.

Though Gingrich appears to be in the Republican primary race until the convention, his candidacy clearly hurts Santorum’s position in Louisiana. In a two person race, Santorum leads Romney by 21 points (55% Santorum/34% Romney/11% undecided). Sixty-one percent of Gingrich’s support on the multi candidate ballot moves to Santorum on the two candidate ballot. Only 22% of Gingrich’s support goes to Romney.

Saturday is the primary, and previous surveys indicated Santorum had only a slight lead. The Magellan survey would seem to blow that out of the water.

Full poll results here, in PDF format.

When we interviewed Gingrich Friday, he agreed that a strong finish in Louisiana – we said he had to win, he said he’d like to win but doing well was crucial – was critical. Third place won’t cut it for him, though – if he’s behind both Santorum and Romney it damages his strategy for sticking around into the Texas primary.

Romney is going to win Illinois tonight. The question will be by how much. But if Santorum is able to win Louisiana by a larger margin, even though the delegate count won’t offset Romney’s margin tonight, the perception might be that Santorum’s campaign is ascendant in the more conservative areas of the country – and Romney will have a real and perhaps growing problem with the narrative that he’s unacceptable to the GOP base. That might be a temporary issue if he can get to 1144 delegates by June, or it could be a fatal problem if he can’t.

But with Louisiana taking on more primary significance this year than in any recent cycle, if Magellan’s poll numbers hold up a major boost to Santorum’s campaign is coming this weekend.