A good place to start would be with the payroll deposits. Even the smalles businesses are required to deposit and report quarterly-- employees and social security numbers. It takes less than 2 minutes to run name and number matches. Duplicate names and numbers or name and number mismatches trigger a visit from ICE. No filings trigger a visit from the IRS. A 0.25% tax on outgoing wire transfers to Latin America (some of which are actually less than wire transfers within the United States!) would finance such a program. Fines for employers who violate the law would finance completion of a much needed wall along our southern border.
"A good place to start would be with the payroll deposits"
A good place to start would be the border! LOL
"It takes less than 2 minutes to run name and number matches"
Well as the article points out, employers have no incentive to check the numbers since the feds are not enforcing the immigration laws anyway.