HGiles: Wow. I think this thread is kind of getting heated. Also, you do realize that by insulting and belittling people for different opinions, you are completely exposing yourselves as just as bigoted and intolerant as you claim US Republicans are, right?
Even more intolerant than Republicans, in fact. Romney may have different opinions than you do, but at least his speech stayed polite, and never included "You're sick, get a life", or "Atheism causes war" (equivalent of StingingVelvet's blatantly insulting "God causes war").
Bush wasn't conservative.
Elmofongo: then he was just republican?
Yeah. One of the confusing things about the 2-party system is that a lot of groups who aren't naturally allies wind up stuck in the same party.
Bush was a big-government corporatist, and not actually very conservative. His winning the election was a victory for bread-and-circuses big-government branches of the Republican parties, and the Tea Party comeback was actually the resurgence of conservatism (small government, balanced budget, representatives should be responsive to citizens, etc)
The Democratic party has these tensions too. I don't know half as much about the inner politics of the Democratic party (since I'm not a member and don't care that much), but at least one source of conflict has been between African-Americans and gay rights, since African-Americans tend to be very against that sort of thing.
In places with smaller, more specific parties I think the party will tie a lot more closely to a person's specific beliefs, but when there's really only 2 games in town most people wind up in one of them even if they aren't a great fit. Libertarians are trying to change that, but not getting very far very fast.