The Bethlehem Steel plant unions went on strike in the late 60's early 70's demanding higher wages. It shut down steel production nation wide which caused manufactures, who were desperate for metal, to look outside North America. This resulted in the rise of imports. It grew offshore steel mills which were direct competition. 63,000,000 Bethlehem Steel works lost their jobs when the company closed up. All the spin off business from coffee shops to road material suppliers who used the slag suffered.

In the 60's, when I was a kid, my dad made it a point to drive by the mill and the massive hump yard (3rd largest in the US) on the way to Rochester to see relatives.

All those unions killed the rust belt, imo.

Democrats want to help unions raise wages higher and impose a nation wide minimum $15,00 an hour wage while China produces cheap labor. They want to shut down the fossil fuel industry in favor of expensive solar and wind, which is unsustainable. Just think how that will kill American jobs that become uncompetitive due to the higher costs.