I mean there's countless anecdotes, which is not good data, but its something. Many, many people (many people are saying..) have noted how crazily divided we have been in the past 5 years. And my above comment got a bunch of upvotes in the last hour so there's more anecdotal evidence I guess.

If it’s on social media then it has to be true. Logical fallacies don’t increase in validity merely because an echo chamber grows or else everything mentioned in r/thedonald could never be a lie.

A small collection of keyboard warriors see division because they want to. Without something to ground their baseless opinions they becomes just as absurd as they appear outside their echo chamber.

Coincidentally my same opinion is also well upvoted in a different thread. That doesn’t make it more of anything.

https://news.ycombinator.com/item?id=25018920