This is a key point about lost manufacturing jobs. For a short time China had dirt cheap labor. That time has past. Still chirp, but no longer dirt cheap. In the steel industry perhaps half the jobs were lost to automation with the reset to strong competition and indeed some dumping for China. I would argue that the miss-west jobs did not go to China, they went to Everett (Boeing), Redmond (MS), LA (Hollywood), NY (wall street), etc. There are always winers and losers in these deals. Traditional manufacturing lost their protection so other US exports (aircraft, tech, media, finance, etc) could gain access to foreign markets. The promise by BOTH parties was that those workers who got screwed in the deal would be taken care of. Some were give retraining that did benefit them, most got nothing. These sorts of disruptions destroy business ecosystems in a locations so new business don't just jump in and fill a factory as a business closes. It took decades to build the manufacturing centers and silicon valley for that matter. Cut the heart out of a sector and it will not rebound on its own for decades.
No matter what anybody says these jobs are not coming back. Manufacturing will come back as a technology and capital intensive highly automated operations, but not with high school education jobs. We must find a solution for angry guys who saw their fathers make $40/.hour who themselves made $20/hour and they see their kids make $10/hour. Perhaps we need to parachute in some of our best entrepreneurs to turn the place around. Perhaps we need to provide incentive to get them to move where the jobs are? I remember in my native Oregon in the '80s as logging wound down there was massive discontent as these folks who for generations made good, if dangerous, living in the woods see their way of life come crashing down. The one gotcha for these logging communities was that they had to move to a new area every few years as the timber was cut. In the 70's the region was over cut and there was no where else to go. These communities lost their economic base and had no way to recover and their kids moved away to make lives of themselves (e.g., Kurt Cobain from Aberdeen, WA moved to Olympia homeless and nearly starving and started sining to make a living). I fear that that may be the fate of many of these rust belt communities.