Well before NAFTA. In 1964 Mexico set up the Maquiladora program which was basically a Mexican government effort to lure US factories into northern Mexico with cheap labor and other enticements. The first paragraph of a Wiki article explains it pretty well.
In 1964, the Bracero Program, which allowed Mexican agricultural workers to work legally in the U.S. on a seasonal basis, came to an end. Less than a year after the end of the Bracero Program, the Mexican Government launched the Border Industrialization Program (BIP) or the Maquiladora Program, to solve the problem of rising unemployment along the border.[2] The maquiladoras became attractive to US firms due to the availability of cheap labor, devaluations of the peso and favorable changes in US customs laws.[citation needed] In 1985, maquiladoras overtook tourism as the largest source of foreign exchange, and since 1996 they have been the second largest industry in Mexico behind the petroleum industry.[3]
Mexico has been a parasite on the US economy for quite a long time.
Thanks for insights.