Right or wrong, Rust Belt residents see NAFTA as at the very least indicative if not the direct cause of the hulking, abandoned factories that form the rust in "Rust Belt."
Free-trade is bad for those whose livelihoods are displaced with nothing to replace them with. Of course, free-trade is easy to blame, but the elephant in the room is that even if manufacturing came back to the US, most of it would be done by robots.
Yeah, my impression is that the manufacturing will be automated, the pay of the job will be low, or the prices will increase in most situations. I guess it remains to be seen whether it is worth it but it seems to me that at the very least the transition will be painful.