NAFTA's fundamental purpose was not to free trade, it was to free multinational corporations from public regulation in the U.S., Mexico, Canada, and eventually all over the world.
Among other things, NAFTA granted corporations extraordinary legal protections against national labor and environmental laws that that they could claim threatened future profits. At the same time, workers and unions were denied the legal status needed to defend themselves in these new cross-border jurisdictions.
It is not just workers in export and import industries who have suffered. Labor markets are connected. When autoworkers and steelworkers are hired for $14 instead of $20 an hour, lower wages ripple into the paychecks of those who work for suppliers, construction contractors, restaurants, and retail stores.
Nor is it just American workers who have taken the hit. Historically high Canadian wages also have been undercut. In Mexico, although some new jobs are created when production is shifted south of the border, the lack of worker protections in NAFTA insured that corporate investors would reap most of the benefits. The gap between U.S. and Mexican wages remains as wide as it was twenty years ago. In the even poorer countries, unregulated global trade has led to the ruthless exploitation of labor -- from teenagers in the sweat shops of Bangladesh to eight year olds working in the gold mines of Tanzania.