I want to comment briefly on the fact, unsurprising to me, but often touted by supporters of this new law, that 70% of Arizonans approve of it, while 60% of all Americans approve of it. Back in 1994 in California, the numbers were even greater in support of Prop. 187, a measure which attempted to remove illegals from receiving any social services, until it was struck down by the courts. The support for 187 did not prevent a seismic shift in California politcs toward Democrats, as a direct result of this proposition, which has remained ever since (unfortunately.)
Public opinion is immediate and reactionary: it will always favor simplistic, direct solutions to any problem. The "tougher" the solution is, the more it will be supported. Civil liberties are never going to be supported by the public; Miranda rights, when they first appeared, were tremendously unpopular. So were most of the rulings of the Warren court which changed this country and put a much greater emphasis on individual rights against the state. This tends to be the reason why, for me personally, I never tout the fact that the public agrees with me- they usually don't, and when they do it makes me uncomfortable.