Could Mitt Romney have been Utah Governor instead of Massachusetts Governor? If so, I think it would be much better for his national career. He had to renounce much of his legacy as Massachusetts Governor in order to win the Republican nomination.
I mean, I think the fact that he won the nomination anyway indicates that it didn't hurt him too much - indeed, as the main non-Tea Party candidate, it might have actually helped that he was viewed as someone who could win over moderates and even liberals. Not for nothing does the Republican Party have its first primary in New Hampshire - I imagine that without Romney having a solid record one state over, he would have done worse there, and I don't know that lower expectations plus an even stronger showing in Nevada makes up for that.
More to the point, Latter-Day Saint conservatism (assuming that Romney wouldn't govern basically like he did in Massachusetts, which I don't think is a given) is very culturally and politically different from Evangelical conservatism - there's a lane for a moderate Northern Republican, but I don't know that one quite as easy exists for a conservative Latter-Day Saint to win over
either country-club moderates
or Tea Party conservatives. If the same candidates get in (absent Jon Huntsman, obvs), I suspect Romney is still the favorite - the only other candidate with his name recognition and appeal outside the Tea Party is Rick Perry, and while Perry is a good candidate on paper his OTL campaign left a lot to be desired - but I don't think there's any reason to believe that he's
more likely to win.
If he had stayed in Michigan, on the other hand... well, he probably would have done about the same as OTL, but still.