In 1980, the GOP vision of free market economics began carrying the day in US economic policy. While Ronald Reagan attracted many "working people," he was probably the most aggressive free trader ever to sit in the Oval Office.
While it's harder to find statistics going back to 1980, it's pretty easy to find them since 1990. Since 1990, the US economy - which has been the lynchpin of the international trading system and is less regulated generally than Europe - has massively outpaced virtually every Western economy in terms of growth. Despite the dramatic growth of Third World economies since 1990, the US is actually a larger share of the world's economy today than it was 35 years ago (26% versus 25%). GDP growth in the US - which directly benefits workers with higher incomes - has dramatically outpaced GDP growth in what were "economically peer" nations in the late 20th century, countries such as the UK, France, and Germany. While the American middle class has declined, the majority of that decline - roughly 2/3s of it - has seen people leave the middle class upwardly.
None of the above is debatable. It seems weird that Rs have run away from the success of their economic project, but sadly it appears to me that it may have to do more with changes in voter preferences due to social issue sorting than it does about economics.
There have been losers from globalization, of course, but it's odd that the current debate in the US focuses only upon them (and seems to ignore solutions like enhancing and encouraging mobility from struggling places to burgeoning ones). And even if the tariff policies are Shangri-La and bring back oodles of manufacturing, what is the guarantee they go to the "right places" that were deleteriously impacted by globalization? I keep wondering if any has thought about this. (And I'm leaving out of the discussion the issue of whether government efforts to revitalize things like defense capacities, shipbuilding, and certain pharmaceutical/technological items, as I think that targeted topic is generally a good question for increased public debate).
I am not a Democrat, and probably will never be one. But if the GOP is becoming an anti-trade party despite this country being one of the biggest trade-related winners, I sure as hell hope the other party defends the global trade system.
I also think it's worth considering the topic of mobility in the US. Historically, if things are down here, moving was a pretty good answer. Why has that changed and is it good?