Probably a little of both, but more of the former.
He already will have a hard time hitting Pres. Obama where it will hurt the most (Obamacare). Hopefully in the general campaign he sticks to the points of Masscare being right for Massachusetts and not for the entire nation, that states should be able to devise their own systems that work for their particular circumstances, and that he worked with the Democrats to come up with something that was at least palatable for Massachusetts.
To pander to the hard right states will force him to answer more claims of 'flipflopper.' And even if he were to come up with a message that appeals there in the primaries, he'd have a hard time beating the more conservative candidates as I don't see how he could 'genuinely' come across as being more conservative than Santorum. If he had a narrative that would seal the deal w/ the social conservatives that he thought would be credible and not cost him moderates, I expect we'd've already heard it. He's not a social conservative, he's close to a fiscal conservative; though compared to the present WH occupant, he is a social conservative.
In the general election, even if Romney doesn't energize the far right, there's no way he loses places like Mississippi. Losing primaries in the deep south, especially in contests where he gets ~30% of the votes, won't hurt him nearly as bad as making a far right social conservative turn will when he gets to the real contest.
If he were getting 10% of the primary in Alabama he might have an issue, getting ~30% shouldn't be a dealbreaker in the delegate count.