Wow - you have written this with palpable zest! Electric! Thanks so much, enjoyed reading.
My take on this is based on Jonathan Haidt's excellent book - The Righteous Mind. We are essentially intuition-driven information processors, constantly scanning the world around us, morally interpreting information and colouring narratives with our unique worldview. A liberal worldview pegs a conservative as a traditionalist, xenophobic, capitalistic, flag-waving, tax-dodging, climate change denying, warmongering, pseudoscientific, Churchgoing, anti-vaxxer incapable of rational thought. Whilst to the conservative, a liberal is a virtue-signalling, tree-hugging, anarchist vegan gay snowflake citizen of the rainbow-world. We readily allow intuition to lead us and then use our rationality to come up with evidence to support our beliefs - the absolute arse-backward way it should be.
I'd really appreciate if you could read my article and feedback - the parallels between your take for WHY Americans seem to be so divided, enraged and partisan and HOW our brains are literally wired to be this way according to Haidt, are uncanny.