I've often heard a funny story about David Horowitz. It goes like this: D-ho, as the histrionically neurotic former 1960s far-left radical turned far-right propagandist is sometimes called, was supposedly irritated by something said by a former '60s comrade who is now a liberal, and responded to his former comrade that if the New Left had won, people like him (i.e., sellout liberals) would have been shot. The former comrade responded that if the '60s left had won, David Horowitz would still be in it.
The cat's opportunistic, in other words.
Now the man who's spend years peddling shrieking right-wing lunacy about Democrats is all about debunking shrieking right-wing lunacy about Democrats. Here, he publishes an effective debunking of conservative claims that the Community Reinvestment Act caused the financial crisis. Here, he takes on right-wing attempts to claim Obama is not a natural-born citizen.
This is how he explains his present task: keeping conservatives from "acting like unpatriotic sore losers and attacking the legitimacy of the new commander-in-chief."