As discussed in this thread, the divisions in the Republican party date back to the Goldwater era, when oppostion to communism caused differing factions (religious fundamentalists, laizzes faire capitalists, cultural nativists, along with others) to believe that were ideologically united.
The fall of communism revealed that there were substantive differences between these factions (as noted above, between, say, unfettered capitalism and religiously derived morality).
But since everyone thought there was some underlying principal uniting them all, they all claim that their particular faction is the “true conservative” one.
The religious guy doesn’t want the billionaire developer to build a casino in his small town in the Bible Belt. But instead of getting together and coming to some sort of compromise, they yell at each other and try to win arguments based on some non-existent principal.
Because this debate has never begun, the focus is on contorting arguments so that ‘liberalism’ is blamed for the disagreements.
I remember in 2006 when Dubya announced his moderate stance on immigration. I was deployed to Iraq with some staunch Bush supporters who were in strong disagreement with Bush’s new immigration stance. But instead of criticizing him, they blamed ‘liberal pressure’. Bush couldn’t be to blame, because he was one of them. (At least until things really went to hell in late 2008, when I first started hearing lots of conservatives denouncing Bush as having betrayed his principles.)
To people who think like this, conservatism can never be at fault, for when it is, it ceases to be conservatism.
Not all conservatives think this way, but for the time being, the ones that do are controlling the Republican party.