As previously discussed, those opposed to the Protect Arizona Now initiative are switching tactics and front groups. The article "Foes of immigration bill shift attack" gives more information:

Steve Roman, a spokesman for the groups organizing to oppose the measure, said Wednesday that Arizonans are unaware of the unintended consequences if the measure is approved. At the very least, he said, it will lead to lawsuits as the courts try to figure out exactly what state and local governments -- and their employees -- need to do to comply with the new laws...

...Roman painted a potentially darker picture of Arizona after Proposition 200.

He said that will range from many state residents having to get new driver licenses to have ready proof of citizenship to paramedics refusing to provide first aid at automobile accidents to those who cannot show they are here legally...

One potential way to counter things like this is to ask why these groups are opposed to PAN. Could there be, oh I dunno, money involved? And, is it right that some people would seek to profit from illegal behavior?