I was pretty chilled when I saw it...this is the stuff that moves countries to the tipping point (think World War One when Archduke Franz Ferdinand was assassinated) and America is a powder keg already from an outsiders perspective.
Will we ever know why, who, how, what and so on? Possibly, but will it be the truth, (whole truth?) I seem to think Trump just won the election because of this...we'll know in about a hundred or so days. (That image of blood on his head, the defiant face and upraised fist...with the Stars and Stripe behind...powerful imagary.
EDIT: And yep, attempted assassination by headshot, no doubt and I agree.