I agree that there's something ugly about the police, even local police, asking citizens for their "papers." There's also something ugly about American citizens being physically searched at airports. There's something ugly about IRS agents prying into nearly all of your personal financial transactions or, thanks to the passage of Obamacare, serving as health insurance enforcers.
The way I see it, the Arizona law empowers police departments to fight crime. The criminals hate this more than anybody, so you will see them disappearing from the scene in Arizona, unless your eyes are fixated on protest mobs and Obama speeches. In other words, if you are concentrating on the bad and the ugly you will miss the good.
One of the reasons I'm proud to be a conservative is that most conservatives understand that something imperfect doesn't equal something evil. I don't want to spend four grand building a fence in my backyard. But I will so my 2-year-old doesn't run out into the street and get killed. So while the fence is an imperfect solution, there is absolutely nothing evil about it, and it's absolutely morally neutral for me to build it. Recently a friend of mine said the Obamacare plan is "evil". I don't like to say that because evil implies intent. I think it's wrong and wrongheaded and mainly because any good from it is drastically outweighed by its bad effects. But I resist saying it's evil because it opens a larger and less productive argument.