Republicans hate Romney. That's why McCain won the Florida primary, a vote many people (mostly referring to pollsters, pundits, and media analysts) felt he would have trouble winning because only Republicans could vote and much of the support that put McCain over the edge in New Hampshire came from independents. But even without the independent voters, McCain still won by a margin of five percent. (McCain = 36% / Romney = 31% / Giuliani = 15% (taken from the L.A. Times.))
Even crazier, McCain won at a time when Americans are reporting the economy as their number one concern and McCain recently admitted he didn't know much about the economy! (Although he quickly backpedaled on that one, Tim Russert dug out the quote and confronted McCain with his own words on last Sundays Meet the Press.) Romney, a successful businessman with a degree from Harvard Business School, who has successfully run several companies and outspent McCain -- still lost!
So why do Republicans hate Romney? Oh, let me count the ways. 1. He's a Mormon (when I think 40% of the base are Evangelicals). 2. They don't know if they can trust him since he's flip-flopped on some of their key "value" issues: abortion and gay rights, not to mention he's lied about owning a gun, exaggerated his hunting experience and flip-flopped again on (gasp) immigration. 3. They're very unsure if he can win against the Democratic nominee. 4. The other candidates hate him because he has such deep pockets and doesn't need to run around the country conducting fund raisers. 5. And finally, did I mention he's a Mormon?
Aside from the above points, however, I think there is a much more basic psychological component. McCain is soft-spoken, affable and looks like grandpa. We all know he served in the military and though, just like every politician, he's flip-flopped, lied, and switched positions over the years, he's still considered a straight shooter.
Romney, however, is the symbol of the slick, successful CEO that everyone hates. Yes, he's successful, trim, handsome, and surrounded by an adoring family, but Americans love an underdog (how else do you explain George W., one of the biggest losers in the world winning the highest office in the land) and Romney is too successful, too polished, his family too happy and his hair too shiny. In other words, he just seems fake.
Obviously, not all Republicans hate him or he wouldn't be doing as well as he is. But, generally speaking, Romney supporters probably aren't as excited or passionate about their candidate the way McCain, Clinton and Obama supporters feel about their candidate. Instead, he's kind of like Kerry was for the Democrats in 2004 -- reasonably competent, insanely rich, and they figure he can't possibly do worse than his predecessor.
Given the choice between Romney and McCain, my bet is that Republicans will eventually choose McCain. After all, how can you not like grandpa?