I actually think there would be a dramatic improvement in a year or two...and by year 5 it would not even be on radar as significant issue. When you let human nature work in your favor, instead of trying to regulate against it, things are soooooo much easier!!!!
Look what happened in AZ when they passed SB 1070. Illegals began to *self deport*! Sadly, the State Senator who authored the bill (Russell Pearce) was re-called :(