While the Arizona law getting all the coverage has been signed into law, it does not take effect immediately -- we won't know for a while yet what the "linear line of questions", to quote an Arizona deputy appearing on the Chris Matthews show, will be that leads to asking for proof of citizenship. If you believe that deputy, the whole are-you-here-legally question won't arise unless you have already done something wrong, like fail to produce license and registration when pulled over by the police.
This is what's being used to counter that claim:
A truck driver apparently born in Fresno, CA produced a CDL and a social security card, but not a birth certificate and was taken away in handcuffs. His wife had to bring his birth certificate over (and brought her own, just to be on the safe side, natch). When the news crew asked:
"A representative at U.S. Immigration and Customs Enforcement (ICE) returned 3TV’s calls after researching the incident and she said this was standard operating procedure."
I guess if you were hoping that Arizona might adopt ICE procedures to avoid detaining and transporting US citizens who don't happen to have the correct paperwork on their person, well, hope is not a plan. I do recognize that many Western democracies require citizens to carry legal identification with them all the time, and even make them register in the town they live in, heck, and even produce lists of names appropriate for babies. Apparently there are some Republicans in a screaming hurry to get to be more like that kind of place. I'm sure they'd also like to arm the police with fully automatic weapons as well.