Fine the employers who hire them, and these people will self-deport.
find the emplohyers who hire them....
That would take care of the problem easily. If the employers had to deal with their actions, there would not be jobs for the illegals in the first place.
A fine will be seen just as a business expense, nothing to worry about - simply another bill to pay, in addition to water and power and rent.
To be effective, people who hire illegals must be personally tried and convicted. Once a few writhing, hysterical CEOs are frog-marched out of court and into the prison, the rest will take notice. Until then ... business as usual.