Alabama Gov. Robert Bentley, who's neutral, says that Mitt's Mormonism might pose a problem tomorrow.
"I think that's a very subtle issue that probably may be a problem in many states – not just in Alabama. I do believe that Republicans are looking to see who can win the presidency, and they're going to look at that more than anything else."
He added that he thought Romney was "so far ahead in delegates [that].... it’s going to be difficult for anyone to beat him.”
Primary voters are supposedly inclusive enough to look beyond Romney's Mormonism in this pluralistic society, but Mitt's religion still seems to be a big deal.
Not only does Santorum (who's Catholic) routinely thrash Mitt among evangelicals, but even Newt (Catholic and married three times) usually does better.
A perfect example of Gingrich doing unnaturally well came in Florida. Romney beat Gingrich by 15%, overall, but Newt actually nipped Romney among evangelicals.
And in Ohio, which Romney won, evangelicals preferred Santorum by 17% over Mitt.
Neither Santorum nor Gingrich is ideally-suited to evangelicals, but Romney consistently trails both guys among evangelicals, which suggests his faith still poses a significant problem in the primary.
UPDATE: I earlier, incorrectly, stated that Bentley has endorsed Romney. He, in fact, is neutral. It's former governor Bob Riley who's supporting Romney.
DOUBLE UPDATE: Alex Schriver points to this interesting bit of info -- Bentley actually turned down Romney's endorsement in his 2010 gubernatorial bid.