Byron York has a lucid explanation at the Washington Examiner of why my libertarian fears may be groundless.
The principal cause for not being concerned? From the Examiner:
“For any lawful contact made by a law enforcement official or a law enforcement agency…where reasonable suspicion exists that the person is an alien who is unlawfully present in the United States, a reasonable attempt shall be made, when practicable, to determine the immigration status of the person…”
…the phrase “lawful contact,” which defines what must be going on before police even think about checking immigration status. “That means the officer is already engaged in some detention of an individual because he’s violated some other law…”
Further, a valid Arizona driver’s license is sufficient presumption that the bearer is in the state legally. If someone is in the country legally yet does not have a driver’s license, they are required by long-standing federal law to carry documentation of their legal status.
In brief, the law is not onerous for those here legally, regardless of their ethnicity. Is there still room for abuse by Arizona police? Sure, just as there is anytime a citizen has a run-in with the law. But in these litigious, cell-phone camera times, the new law seems like a reasonable attack on a vexing problem.