Do yourself a giant favor and read this:
Holly's Hystrionics: An Illegal Immigration Rant
And then read this:
It really opened my eyes about the illegal alien situation and its ramifications in this country. Here in Virginia it is not uncommon for workers from across the border to say how they can work here for a few years at minumum wage, return home, and not work for three or four years. Certain commodities that are extremely expensive 'back home' can be purchased here, sent 'home' and resold for a nice profit.
But these two bloggers do a much better job than I do at explaining this situation, and both deal with it on a much more personal level.