I think part of what's going on is an extreme polarisation of political discourse in the US (at least, online. No one talks to me about politics when I'm there in person). On other forums I visit too, it seems that anyone critical of Trump is classed as a 'Leftist' - by which seems to be meant something more akin to 'Satanic Nazi paedophile' than 'supporter of left-wing political ideals. Conversely, anyone who is insufficiently critical of Trump is considered a closet white nationalist.
This sort of thing has always happened, of course, but it does seem much more prevalent to me. Not sure how accurate that perception is.
Secondly, I get the impression there's a lot more maligning in general at EvC these days. I was reading through some posts from back in the day a while ago; and came across an exchange in which a poster suggested another was a liar. This brought rapid moderator warning and an apology. I think things would be improved if we went back to a much more strict interpretation of the 'Argue the position, not the person' rule; but just my opinion. It's not like I would have the patience or time to actually do the moderating.