If we want to stop illegal immigration, let's hold accountable those people who hire them. As long as there is demand for illegal labor, people will keep coming. If they can't find work here, there's no reason for them to be here, and they will leave, or seek public help and be deported. I say we hold such employers with criminal strict liability--that is, they need not even know if a person is illegal, and still be charged with a crime. This would create an affirmative duty to verify someone's identity before hiring them. An anecdote, I worked at restaurant 20 years ago, the INS (before Homeland Security) found out some of the prep cooks and dishwashers had fake social security cards, so the Chef had to fire them all, but he told them as soon as they had new fake social security cards, he'd rehire them, which he did; they were still working there nearly a year later.