I'm not sure the Trump phenom is a mystery. Mostly 2 things:
(1) middle class econ despair due to automation, outsourcing, etc. (Which @BernieSanders also decried)
(2) revulsion at snobbish, hashtag leftism with its pronoun checks, intersectional gibberish & smug virtue signaling https://twitter.com/AndyVonasch/status/1324061730972950528

I don't see any solution, because (1) American conservatives are in complete denial about the needed overhaul to the American welfare state that's going to be required in the face of the gig economy, income inequality etc., while (2) on the left....

the left now increasingly just lazily blames every setback on white people being racist, further alienating them from ordinary voters (including a growing number of voters who aren't even white), which in turn exacerbates their need to claim everyone is racist. A vicious cycle.

I'm saying this from Canada, which has a healthier political dynamic, bcuz (1) our conservatives made peace with the welfare state. And (2) on the left, smaller parties such as NDP siphon off the hardcore social justice types into performative sideshows. E.g. @theJagmeetSingh

One problem with US is the limitations of a 2-party system. A single party on the left, the Dems, has to both (1) aspire to run a global superpower, while (2) simultaneously giving social media head pats to every nutbag SJ movement on campus. So the party identity is incoherent..

But the exact same is true of republicans, who are trying to convince voters they can run multi-trillion dollar welfare state programs like social security & medicare, while also being led by populist loons who think covid could be cured by hydrochloroquine and other qanon crap

In an alternate universe where you could redesign the US political system, you would make room for smaller parties to siphon off these fringe constituencies, so they wouldn't get a chance to take over the mainstream parties that the US needs to run government as adults.

In fact, I'd be interested in seeing a quantitative study on whether parliamentary systems (which tend to allow more parties, & break the deadlock on a 2-party dynamic) have done a better job resisting polarization & populism (though I realize Israel is an obvious counterexample)

This thread is already too long, but I will make one final note that parliamentary systems permit more regional parties. regionalism is conservative (in the Euro sense), & can blunt the force of ideological manias (as Quebec has done in the face of anglo social justice fervor)