Sorry snowflake, but Mexico exports a number of products to the US that did not originate from the US. As an example, Mexico's number #2 export by sheer revenue to the USA alone is illicit drugs to the tune of an estimated $66-billion annually only to be barely outpaced by cars by $22-billion. The other top exports are all organic Mexican so yes a tariff would work as most Americans stopped buying the Mexican cars labeled as GM long ago and GM's recent bankruptcy proves this.