But if you're saying that we are all violent beings, that there is no essential distinction between the madman and ourselves, then there is no reason not to treat the madman as we would someone who did it for political reasons, and open a discussion on the climate that allows such monstrous flowers to germinate and blossom.

As you'll have gathered from reading my posts, though I do try to follow yours and have nothing but respect for the depth of your scholarship, I can't be doing with the nihilism thing. We have the animal inside us, but we also have the reasoning being, and even a madman has a choice and a reason for choosing to do what he does. But whether this chap was mad or not, the fact of the deliberate provocation remains; the fact that a certain politician made it clear that in her opinion this other politician was a target, something to be (metaphorically, perhaps) shot at. And someone, literally, shot at her.

It may indeed be that we are non-beings trapped in a Kafkaesque nightmare of purposeless motion and reasonless thought, doomed to live out our span and vanish into the oblivion of, er, oblivion. But while we wait for that, we might as well try and stop people shooting each other.