They don't have anything to agree on because politics isn't just a hat someone puts on and takes off anymore. It's become an identity that defines people; an ever-present dark cloud that accompanies people wherever the go and can no longer be ignored.
I guess there's been a culture shift from years of the media and politicians not promoting civility in the public arena. Conservatives are probably facing the most ostracization for being real or perceived Trump supporters. I'm sure someone has written a book on this because it feels like there's a lot to say.
"Neither party seems to be worried about the truth..." You nailed it with that single statement. It's less about reason/logic and more about inflamed emotions.
