Here's a Townhall.com article discussing Mitt's trips to South Carolina. Here are a couple quotes that indicate maybe the outlook isn't as bleak as some may tend to think:

Dr. Bob Taylor is a dean at Bob Jones University, an evangelical school in Greenville, and generally the political thermometer for the most faithful of South Carolina voters. Political types close to Taylor quote him as not viewing Romney's religion as a crippling issue. As long as Romney maintains his faithfulness to conservative principles, the faithful will accept him.

***
Scott Malyerck, Executive Director of the South Carolina Republican Party, believes South Carolina voters have been thoroughly impressed with Romney. “His remarks have been well-received by both moderate and conservative Republicans,” said Malyerck in an interview with Townhall.com.

Continuing, Malyerck said, “I think Mitt Romney understands that if he decides to run for president, he will spend many weeks talking to South Carolinians about the future of our country and the challenges that lie ahead. So far, Republicans seem to be impressed with him, like his enthusiasm, and enjoy hearing what he has to say. I suspect we will be seeing a lot of Governor Romney in the future.”

This link has the C-SPAN video of his South Carolina speeches.

So my question is, how much of a factor is his religion really? If he can show that he actually is a Christian and doesn't have horns, won't that be enough? I don't want to see him get to the level of George W. Bush as far as religious pandering, and I don't think he'll have to. If he goes too far -- picture Rick Santorum with a Bible in his hand everywhere he goes -- people will see through it and it will focus more attention on the doctrinal differences between him and the Religious Right.