Gotta take issue with this.
I'm having a hard time coming up with a "right-wing fanatic" who went on a shooting spree.
Do you have someone in particular in mind?
To be honest, only one that even comes close, comes to mind. And even in his case, there are many who would convincingly argue his was a left-wing cause.
I think I wasn't willing to devolve the argument to that set of points, I just wanted those who are left of center to be able to read this and maybe not get stuck on the name-and-blame-game, but instead skate past that point and get the larger -- and far more important -- message.