The undiagnosed problem is that you cannot have a work force that speaks two different languages. If workers at the same job cannot readily communicate, it is a recipe for disaster.
Thus ONE ILLEGAL WORKER rapidly becomes an entire illegal workforce.
What happens to the citizen worker?
HASTA LA VISTA, BAYBEEE!
Cheap labor on the front end, tons of costs on the back end.
A few years ago the mexicans had a work stoppage over an immigration law signed by Sonny Perdue. Well all I can say is that it backfired big time. Work still got done and the radio stations and newspapers were filled with comments on how pleasant it was to work, travel and shop.