This article gets at exactly what I'm saying. Of course the retaliation was worse and that senator is an awful human being to begin with. This kid did what many of us would dream of doing. But actually endorsing a "mild" act of violence against a politician you disagree with is setting a very dangerous precedent.
Just wait until your favorite 2020 candidate gets sucker punched in the back of the head while on the campaign trail. The nutjob who does that will point to this kid and say "well that kid did it and everyone praised him." Its beginning down a road you really shouldn't want to go down.