You mean the same "qualifications" we have now?
Those who refuse to leave and are caught should be sent back home and banned for at least a decade, if not life, from returning.
Wouldn't hurt. You would need fingerprints and/or DNA, not just a potentially phony ID card. But we would need better class of congresscritters than we have now to pass such a bill.
In any case, I don't think it would work without mandatory e-verify.
You are right and I am writing of an ideal situation. It could work, if we had the will. But we don’t. America has become a land where feelings rule and it doesn’t take many sob stories before the rule of law and our principles are thrown to the wind so someone won’t be hurt.