People will take the best job available on the market. If bringing back manufacturing brings back a lot of subsistence level jobs, you won't have people in midd

People will take the best job available on the market. If bringing back manufacturing brings back a lot of subsistence level jobs, you won't have people in middle class jobs leaving those jobs for the subsistence jobs. The only people who take those new jobs are those who are in a worst position than what the subsistence level would provide them, and thus are better off with the subsistence level job than without. This is basic free market economic theory that any economist (other than perhaps Marxians) would agree with.