But these are not your father’s manufacturing jobs. Many of the companies are locating their new plants in right-to-work states where it’s less likely their workers will join a union, and the prevailing wages are far lower.

In fact, nationally, the average wages of production and non-supervisory employees in manufacturing are lower than they were in 1985, when adjusted for inflation. In September, those employees made an average $8.63 an hour, in 1982 to 1984 dollars, while they made an average of $8.80 an hour in 1985, according to the Bureau of Labor Statistics.

“We’ve not seen the wage growth that we would love to see,” said Jan McKeel, the executive director of the South Central Tennessee Workforce Alliance, which works to train people at local career centers and has prepared the Tennessee workforce for the new jobs in this economy. “I think we sort of mirror the national statistics you’re probably seeing in some areas, that we’re in wages equal to the early ‘90s.”

Onshoring is generally viewed as a positive turn, a corrective to the job losses of the past 20 years. Towns that lost thousands of jobs after NAFTA, where empty factories still stand, could benefit from a manufacturing boom. But the quality of the compensation raises the possibility that in the globalized economy of 2015, manufacturing can no longer provide the standard of living that Americans seek, and America will need to find a different way to restore the middle-class strength it once knew.

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The Spring Hill GM plant is perhaps an example of the best that onshoring can bring. The plant is unionized and the jobs—with their profit-sharing perks and high-quality health care—are good ones.

This is true even for the plant’s so called “second-tier workers”—new hires who get paid substantially less (topping out at $19.28 an hour) than the long-time workers (at $28 an hour), in a system the union agreed to during negotiations in 2007.

Crystal Conklin had lived paycheck to paycheck, working odd jobs in retail office work, before she was hired as a second-tier worker at the Spring Hill plant a few years ago. Thanks to her $18 an hour wages and subsidized health insurance, she was able to save up enough to buy a car last year, and also bought a house. She wants her 17-year-old son to start working at Spring Hill while he goes to community college.

“Working at the plant has just allowed me to come out of this hole that I was in, in life, going absolutely nowhere, not advancing in anything,” she told me. “Now I’ve bought a house, I drive a brand-new vehicle.”

It may be no accident that Spring Hill is one of the American cities where the gap is smallest between the highest-paid and lowest-paid workers, according to NerdWallet; the average household income for the top 20 percent of workers is $157,191, while the average household income for the bottom 20 percent is $26,735; the middle 20 percent made $74,214. Though those differences may seem big, they’re among the smallest in the nation; thanks in part to the union, there isn’t as much income inequality as in other U.S. cities and towns.