It's my understanding many of them deal in cash. Legalizing them and hoping to pick up some of their money by means of the income tax is not the solution. Deport those who are here illegally; that's the rule of law. For those still here, abolish the income tax and pass a national sales tax. When they go to WalMart for a new color TV, you'll finally get them to pay some portion of the cost of government.
"It's my understanding many of them deal in cash."
I've seen it. Tell me where (or why) you get $100 bills if you aren't being paid in cash and you have a bank account?
ATMs only deposit $20s.