American factories keep voting with their trucks — for Mexico

While the White House rehearses a trade war with Canada, American companies continue a quieter migration south. The reasons are not mysterious and they are not new: cheaper production, a clock that still beats in the same hemisphere, and a border that — for freight, if not for people — remains one of the most practiced logistics machines on earth.

Monterrey, Saltillo, the Bajío, and the industrial parks that have grown like a second city along the Rio Grande are absorbing lines that used to live in Ohio, Michigan, and the Carolinas. The pandemic taught purchasing managers that a container from Shenzhen can vanish for three months. A trailer from Nuevo León can be on a Texas dock before the meeting ends.

Mexico’s pitch is arithmetic: U.S.M.C.A. rules of origin, a labor market that still answers the phone, and energy that is a political fight in Mexico City and a line item in Dallas. There is a contradiction the campaign trail will not resolve. A country that wants to punish partners with tariffs is also a country whose factories have already voted. They voted for Mexico. The ballots are trucks. They run all night.