Apparently you didn't read, or you didn't understand, Samuelson's essay, especially the part where the finished goods have been across the border multiple times, making them a cooperative effort between our two nations. Those are specific products for specific larger assemblies in many cases, and the disruption of the complex net of manufacturing would cost industries huge money in lost capital, lost time, and lost sources. I would guess the immediate loss of capital in Mexico (and in the US) would hit investors on both sides of the border, and greatly increase the scarcity and cost of major goods to consumers in both countries. What is the gain? I see none.  The manufacture of widgets for American cars would simply go to China. Much of it has, already. And not only for us. Honda small engines now are manufactured in China, as are many auto parts and subassemblies. You would start a trade war over an insignificant deficit with a neighbor we need to prosper.