It may help if the left began by not assuming that there was a binary and that they are the good guys. There's some excellent stuff here - but I'm not convinced that it isn't partisan. There were many on the Left who hated Trump before he'd done anything as President. Like your Pelosi hater, that came from ideology not from the reality with him as President.
Don't get me wrong, Trump was an awful President but I think there's a compelling argument that the average white middle class American has moved to the poltiical rght because of the actions and intolerance of the political left. Your average working class white voter doesn't like being told he's now a racist, misogynistc, transphobic, anti-semitic thundercunt - no matter how true it might be.
Whether or not they then fell into the waiting maelstrom of Trumpian non-reality and radicalisation is largely dependent on their own psychology. It's going to take a long time to deprogram these people - and it can't be done whilst there's an insistence on identity politics as the modus operandi of the country. It can probably only be done by gradually bringing people back to the centre ground and concentrating on the things that unify the human experience - nothing about the insistence of grouping by race, sex, class or gender does that, no matter how progressive it seems.
I think Joe Biden gets it. I hope for your sake he does.