“That will either help pay for the wall or force illegals to ride or drive
themselves back to Metico to deliver their money personally.
And that gets them out of our country and back into their country.”
Or they could put cash in the mail.
Or a black market develops where illegals pay drug cartels to deliver money back home
Or mail a pre-paid debit card, or send money via PayPal, or mail gold coins, etc.
The PayPal and Western Union and Money Gram are the easy ones to capture, but the safest way for the send to be assured the receiver actually receives SOMETHING. Anything going physically will soon become a target for enterprising criminals in Mexico. So it is a matter of finding the tax level where the safety of the transaction is worth paying the tax. 10% on $25B/yr would take 5 years to pay for the wall and thereafter would pay for a tripled Border patrol.
Never tried to send a $10.00 bill to a grand child have you?