I think that people like Christopher Lasch, who were predicting this flip decades ago, have turned out to be prophetic.
It's not just that issues flip, but whole demographics flip. In this case it's the gentrification of the left, and society polarising around educational credentials, that's probably the big driver. You occasionally see the class work here, where someone will turn up who's very invested in being left wing, and that takes the form of deferring to credentialed experts and bemoaning "populism". You see it in a much cruder form on US Democrat subreddits, where it's very common for posters to boast about their degrees and describe GOP voters as inbred yokels.
Those Democrats imagine that they're advocating on behalf of the working class, and then they're bemused that they lost the working class vote to a guy who lives in a golden tower.
It's worth checking out Patrick Ruffini's book Party of the People for hard data on this. Ruffini is an interesting guy - a Republican pollster who doesn't like Trump, who thought Trump would go down to a landslide defeat in 2016, then figured out that maybe the crass game show host had intuited something about the electorate that he hadn't seen.
It's important because the most lasting Democratic advantage for almost 200 years, since Martin Van Buren founded the party to support Andrew Jackson's presidential campaign, was its brand as the party of the little guy opposing the elites. That's what's flipped.
What was the single Trumpiest ethnic group in the November election? Not white voters, but Native Americans. Not many of them work in prestige graduate professions. They live in unfashionable places and work in jobs like construction or plumbing.
None of us think Trump is an intellectual, but he's not stupid and he can spot an underserved market. And he's got people like Vance who does seem to understand the realigment and wants to lean into it. One thing to watch will be the nomination of Lori Chavez-DeRemer as labour secretary. She's been one of the handful of consistently pro-union Republicans in Congress, very close to the Teamsters, and the old-school Reaganite conservatives hate her nomination.
And for the Democrats, see also UK Labour, whose Camden based leadership gives off a strong vibe of "We don't really like these low-status Red Wall voters. Here, Nigel, you have them."