The Republican presidential primaries were hilarious because they obviously did not have a candidate that could hold together their coalition of cultural conservatives and big business. McCain was the best they could do, but there was still a substantial protest vote for Huckabee (and Paul). For example, they got 22% and 7% in Rhode Island, respectively, after McCain had effectively locked up the race. In the end, what Sarah Palin did was give the religious right an excuse to come home. I don't think much further hair-splitting about how and why is going to hold up much six months from now.
The corollary here is that there is a long term question about whether or not Palin will be supported by Republican business interests in the long run. She seems like a more assertive populist than they'd feel comfortable with. I can't see a businessman feeling like their investments were safer with Palin than Obama or Clinton, but maybe I'm wrong.