Fair point, I can only speak directly about my local experience.

That's true but we, that includes me, can look around and see what's happening beyond our State and National borders to see if a theory fits.

Realistically, the standard of living has been falling for a while.

IMO that's the crux of the problem right there. The Standard of Living has been falling everywhere and it's been falling faster as "Globalization" took hold. The real issue though isn't trade between countries that have roughly similar economic systems and lifestyles, it's the one sided importation of goods between countries that do not have roughly similar economic systems and lifestyles.

The problem with Globalization is that it tears the floor out from underneath the vulnerable. The under-educated and the poor struggle to make a living because their jobs have been shipped away to another country where someone can live for less and thus work for less. It's a race to the bottom.

Those vulnerable people, and even the once privileged who've watched their livelihoods ripped away, are increasingly desperate to find a way out of their situation and so they're increasingly turning to the only people who seem to care. To paraphrase a bit "It's the (real) economy, stupid!"

This isn't my idea either as this outcome was widely predicted by Union Bosses and Business Leaders during the Clinton Administrations runup to NAFTA and MFN Trading Status for China.

If they were correct, and it appears they were, then the only way to stop the madness is to re-onshore the jobs as much as possible with a special focus on geographic areas that have the highest imbalance. The U.S. started doing it under the Trump Administration and the Biden Administration has accelerated the trend. If everyone will just hang tight for another 12-18 months the effects will start to get really noticeable and the Right Wing rise will ebb away.