The goal of SB 1070 has already been mostly accomplished -- creating a climate of fear and loathing to drive away Mexicans, and not just those that are here without documents. This law hurts everybody -- it also harms non-Mexican residents of Arizona by blowing a huge whole in their already reeling economy. And it has greatly harmed all of America, and our reputation as the kind of nation that would never codify such ugliness in our laws. And it's too late for the damage to be undone.
Nothing like listening to xenophobes and racists and hurting your own economic self-interest.
And that, is not just the nasty underside of American politics, it's the nasty underside of any Democratic system. That's not to advocate some other system, which have even worse problems -- but that doesn't mean it should not be recognized.