Well, the guy who did this appears to be quite the nutcase.
However, the language of the Right's leaders has been laced with violent rhetoric for some time now. It is a false equivalence to state that the left has it's loonies. Of course it does. But you will find no blood soaked imagery coming from it's leaders; as compared to the reckless statements of the Right's Palin, Angle, Bachmann, Limbaugh, O'Reilly, Beck, et al.
They need to knock it off. Now!
Also, as the party of "Personal Responsibility", Republicans need to man up, and acknowledge that their language has had consequences. The way they are weaseling out of accepting any blame, while accusing the Left of attempting to take "partisan advantage" of the situation, is pathetic and rings completely hollow.