David Brooks Now Totally Pathological
Just go read the whole thing.
Moderate Republicanism is a tendency that increasingly defies ideological analysis and instead requires psychological analysis. The psychological mechanism is fairly obvious. The radicalization of the GOP has placed unbearable strain on those few moderates torn between their positions and their attachment to party. Many moderate conservatives have simply broken off from the party, at least in its current incarnation, and are hoping or working to build a sane alternative. Those who remain must escape into progressively more baroque fantasies.
The prevalent expression of this psychological pain is the belief that President Obama is largely or entirely responsible for Republican extremism.