So far I've already seen two comments dismissing this as an evil plot to drive down labor costs. I hear this argument a lot and I can't over emphasize my absolute disgust for it. It seems to cross both class and party lines.

There are human beings who are willing to risk life and limb, to separate themselves permanently from their families, to endure unspeakable hardship and constant fear of being deported simply for the opportunity to work -- and the only thing us middle-class, educated, privileged people can think about is that these people might dare compete with us! Excluding them from opportunity simply because they were born on the other side of some arbitrary, imaginary line is cruelty and selfishness beyond belief.

(This is not condoning the original link above or whatever it might stand for. It seems a little impossible to tell.)