Let's just be brutally honest and direct, okay?
The primary motivation of what remains of the Republican Party and the right wing fringe in this country is no different than what drives all fundamentalist groups throughout the world - FEAR. Specifically, fear of the Other.
The driving mania behind a ludicrous economic philosophy that presumes that welfare and socialism for the wealthy is good for the country, while the same for working class citizens is destructive is rooted in a primal terror - of all races other than one's own, of femininity in general, and sensuality overall, of the young and elderly, of artists, of truly spiritual people and of any whose overt sexual orientation is other than heterosexual.
Who does that leave, obviously? Pseudo religious, pseudo-straight fanatics between the ages of 35 and 65, lacking in any real depths of sensuality, artistic sensibilities or true spirituality, latently riddled with castration anxiety and misogyny, who are full of paranoid rage and the hormonal balance of a pubescent boy.
Oh... and Ann Coulter.