A Washington Examiner opinion column is making the case that the United States auto industry's survival no longer hinges on tariff rates at the border but on whether Chinese automakers can be kept out of Mexican assembly halls.

The piece, headlined "Tariffs won't save Detroit — locking China out of Mexico will," recasts the trade fight as a geography problem rather than a duty problem. Detroit sits on the wrong end of a North American supply chain that Beijing is methodically threading itself into, the columnist argues. That alone makes Mexico the lever worth pulling.

Why Mexico matters more than the duty line

Mexico ranks among the world's top vehicle producers. American automakers run sprawling assembly complexes there, with components crossing the border multiple times before a finished car rolls off the line under USMCA rules. The Examiner's premise is blunt: any tariff regime is only as strong as the gate next door.

If a Chinese-owned plant sets up shop on Mexican soil, it inherits the same USMCA preferential access Detroit's transplants enjoy — without paying the labor, IP and union costs that come with operating in Michigan. Tariffs cannot tell the difference between a Ford truck and a BYD sedan rolling through Laredo.

The bottom line: the duty line is paper-thin if the assembly hall next door is on someone else's payroll.

The Chinese factory hunt, briefly

The strategic argument is not theoretical. Chinese automakers have publicly explored Mexican assembly for several years. BYD, SAIC and JAC have all been linked to site searches, joint ventures or dealer expansions in Mexican states bordering the United States. A handful of those plans have been paused or cancelled. The column treats the freeze as weather, not climate.

Why tariffs won't carry the load

Both the Biden and Trump administrations have leaned on Section 232 and Section 301 duties to slow Chinese auto imports. Tariffs raise prices fast and, over time, prod domestic investment. They do not, however, block a Chinese-owned plant in Mexico from rolling vehicles into the United States under a North American trade preference. The author calls this gap the policy flaw Washington will not touch.

There is also the math. A 100% tariff on a Chinese EV still leaves a duty-free vehicle if it was built in a USMCA plant. The duty line stops at the border; the supply chain does not.

The bottom line: tariffs buy time. They do not buy sovereignty over who builds the car.

What to watch next

• Whether the next USMCA review cycle includes binding restrictions on Chinese-origin shareholders in Mexican auto plants.
• Whether GM, Ford and Stellantis formally back a "Mexican firewall" position.
• Whether Mexico's federal government tightens foreign-investment screening on Chinese assembly projects.

The columnist's verdict, in plain words: stop measuring protection in duty percentages. Start measuring it in factory ownership.