We don’t have to deport a single one - just stop employing them and stop giving them welfare.
The mechanism is already in place to handle this, it’s called “E-Verify,” and most if not all major U.S. corporations already use it to determine immigration status.
I promise you, when they can’t work here, they leave.
Once the wall is up Trump should announce that “The US Government will issue x-thousand Green Cards for Citizens of Mexico this year. The ONLY place where you may file your application is in-person at the US Embassy in Mexico City.”
They’ll self-deport faster than you can say guacamole.
Will Obama’s Social Security number pass E-Verify? NOt that I have heard.