They either sign up and follow the (new) rules or they are automatically deported if caught
Now the problem is .. enforcing the laws on a Local/City/State level .. because the Feds can't enforce the laws all on their own if the local level will not help
We have laws on the books that cover that now. Do we have the ability to enforce it? Not today. Are we willing to create the massive bureaucracy necessary to do it? I doubt it. Any attempt to have widescale deportations would invite reactions from the ACLU, La Raza, the Catholic church, the Dems, and the illegals who will demonstrate in even greater numbers. We will have a backlog of court cases.
Now the problem is .. enforcing the laws on a Local/City/State level .. because the Feds can't enforce the laws all on their own if the local level will not help
And who is going to pay for the costs associated with the enforcement? I agree we need such cooperation now instead of sanctuary cities. We have laws now that govern the treatment of illegal aliens. We really don't need new ones except to legalize the illegals. Problem solved--on paper.
And Richardson here in NM has let it be known, though legislation/executive order (can't remember which) that no state employee, from welfare to state police, are to ask the immigration status of a person they come in contact with.