If it's racism, then how do you explain these numbers?:
"There were the traditional racial and gender gaps. Whites favored Jindal by a two-to-one margin of 61 percent to 29 percent for Blanco; blacks favored Blanco by a more than eight-to-one advantage of 83 percent to 11 percent for Jindal. Among all men, Jindal held a 53-39 advantage, while Blanco had 46-43.
Jindal held a 40-point advantage among white men, 66 to 26, but only a 24-point advantage, 56 to 32, among white women. Among black males, Blanco had a 65-point advantage, 79 to 14 for Jindal, but among black females, Blanco's advantage was 78 points or 86 percent to 8 percent for Jindal."
http://www.theadvertiser.com/news/html/E988BE4C-8550-4739-9C14-69A573364052.shtml
By more than 2 to 1 whites in Louisiana will vote for a dark-skinned candidate of Indian descent over a white woman. Therefore, the explanation has to be more than just race. It seems clear that religion, specifically conservative Christianity, is the motivating factor for this vote. They are Republican, and will vote that way regardless of the skin color of the Republican candidate.