[superfrank]

I don't think that's all of it. Politics has continually gotten more polarizing over the 20 or so years. I don't think this is the worst it's ever been in the US, but it definitely seems like the Trump era is the worst it's been since mass adoption of the internet. Because of things like 24 hour news networks and social media, we're also reminded of our differences much more frequently than we used to be.

I think politics is just a bigger part of peoples' lives now and we're seeing that play out in real life as well as in internet communities.