The way this conflict escalates doesn’t typically resolve around disputed “facts” at all. I would say it typically revolves around disputes in the interpretation of facts, or the attribution of motive, or the likelihood of particular outcomes… These interpretations or opinions are naturally quite seperate from “the facts”, but the appetite for propaganda demands that each faction asserts their own interpretation as “the correct interpretation”.
This article for instance doesn’t really present many disputed facts. But it does describe what it believes was the motive for a particular decision, and asserts that this explanation is clearly the correct explanation.
I think this sort of thing has been around forever, and the only thing that’s different now compared to 20 years ago, is that the internet has made controlling the flow of information a slightly more efficient endeavour.
Seems like the American public have either been worn down into non-engagement or radicalised, and I think it's a combination of the designs of politicians (the partisan game is simpler to play and costs less and is more predictable than the one that is focused on societal progress) and that a lot of people would rather believe that the only thing between us and a better society is the evil 50 senators in the other party. Distracts them from having to take personal responsibility for their contribution (or lack thereof) to society and that many of our problems don't have obvious legislative solutions.