I'm thinking this could be implemented right at the border on every truck or train that is shipping goods (or possibly illegals) from Mexico to the US. I propose a fifty dollar fee per truck and per train car to help the USA pay for the additional border security due to their transporting of non citizens to our border. And of course the high quality day care and accommodations we are providing them while we try to figure out if they really are parents or impostors or criminals. No more free ride for Mexico. No more Uncle Sam being played for a chump. What's that Mexico? You don't like paying the Tariff? Then stop shipping them.