I don't take it as satire (assuming he wrote it), but I see no reason to think he is a "far left liberal progressive." He supports George H.W. Bush, Chris Christie and John Huntsman, among others - you won't find many Occupy protestors who would say that.
It appears to me he, like most thinking people, adopts views from both sides of the political aisle. In any case I see no reason to believe this is a politically-motivated crime, and anyone who tries to turn it into that is trying wedge a square peg into a round hole. It's like saying Sandy Hook was politically motivated because Adam Lanza was politically conservative - one thing has nothing to do with the other (as opposed to something like the OKC bombing, which was explicitly a political act).