People forget that this is also exploitation. As soon as a worker gets "amnesty" the employer is just going to look for someone else that's illegal and easy to intimidate! Those who suffer most from black market labor are recent legal immigrants. Anyone at the bottom rung, or starting out, is going to suffer.
This "compassionate" business is crap. There's no compassion about it--the truly compassionate thing is to protect the law-abiding by punishing the law-breaker.
Worth repeating. I wish Bush would grasp this fact.