What you are failing to take into account here is the people who will not vote for a Mormon. Period.
They won’t vote for Obama of course but they will sit out the election before they will vote for someone they think is a member of a cult. Southerners do not like Romney. Tonight’s results should make that clear. The reasons for their dislike are many but his religion is a big part of it for a certain demographic. Some of these people will undoubtedly vote for the Republican nominee in the Fall, no matter who it is. But I am confident there will be a significant number of evangelicals who will sit out the election if Romney is the nominee. Will it be a large enough number to cost Romney a state? I don’t know, but if I were one of his advisers I would be concerned about it.
And you can bet David Axelrod has a strategy ready to make this work in his guy’s favor.