Isn't it more likely that this is a false flag operation designed to distract from the Epstein birthday card signed by Trump? The timing is suspicious and there's certainly a lot of bandwidth given over to a single shooting, compared to the school shooting on the same day (three shot).
Kirk would seem like an ideal target as he has a high media profile and is not involved in running the government. I would guess that the aim is to promote civil war and thus provide an excuse for martial law.