I never cease to be amazed at the number of American (and European) companies that operate in Mexico*. As our road trip wound through some of the industrial centers of he country I saw corporate brands you would deem exclusively "American", each taking advantage of the cheaper labor and costs in order to remain competitive domestically.
Much angst was generated locally and nationally when United Technologies planned to close its unionized Carrier factory in Indianapolis. The Trumpster even got involved. Lots of folks vowed to never buy a Carrier again. Of course they will forget this notion in fifteen or twenty years when they finally need a new furnace or air conditioner. More to the point, I read nothing about boycotts of Lennox, who, by the way, has a factory in...Mexico.
The big car companies are there and so are the tier one and tier two suppliers. The big trucks are made there too. Thus so are the suppliers for those plants.
Often these factories are supplemental to facilities in the States, offering components or sub assemblies. Sometimes the end products are sold within Mexico, or most often both.
And the US presence isn't limited to industrial products. Consumer goods can be found too. Your favorite Bic pen? I went past a factory wearing their brand. That recliner you are sitting in? They are there too.
The point is we are in an international business world. No amount of isolation rhetoric is going to change that.
* and China.