A farmer works at an avocado plantation in El Carmen ranch in the community of Tochimilco, Puebla State, Mexico, on April 5 JOSE CASTANARES/AFP/Getty Images

The costs of any tariff imposed on Mexico will ultimately be passed along to American consumers. (Remember: Tariffs are paid by importers, not by exporting countries.)

So what does that mean? Tariffs will affect the supply chain for ...

The US auto industry

Machinery

Medical instruments

Avocados and tomatoes (and plenty of other fruit and vegetables.)