If you are not familiar with Operation Wetback, 1954, perhaps you could still learn something.
There were NO court cases.
As for law enforcement officers' expense. I would rather spend the money, whatever the cost, to a geometrically increasing population of mobs inimical to our basic system, most criminally inclined, embedded in a corrupt culture which propagates endlessly for generations as far as the imagination can grasp.
I would agree to exceptions for families who are demonstrably self sustaining for at least two generations, haven't bred any gang-bangers, not recipients of any kind of ongoing taxpayer-funded aid, and not benefitting from special financial privileges not enjoyed by regular non-welfare citizens.
RE: There were NO court cases.
That was THEN. This is NOW.
We WILL have court cases with the grievance industry tying up the courts for a long time.