Devil advocate would be more that guy that tried to shoot a bunch of GOP at a baseball game a few year ago, although iirc he wasn't exactly a model democrat like this... specimen... seems to represent what the GOP is becoming.
But yeah, its clear that the level of discourse as markedly gone down in the last few year, let say, to pick a random year, 2016. Apparently Micheal Flynn has gone full christian warrior cultist and he goes around making conference where he more or less call out for certain people to be assassinated, including Pelosi.
I really don't know how to descalate the situation, closest I can think of would be for the education situation to be removed from state power and reformed to make sure next generation aren't raised by GOP picked people and just wait for a generation change.