by ear » Mon Mar 28, 2011 12:34 am
That law makes it a STATE crime for an unregistered alien to be found in Arizona, giving state and local police the power to arrest them (for trespass) and turn them over to federal authorities.
Apparently the Arizona legislature (and their constituents) and the governor believed that the federal agencies were having difficulty enforcing the 1986 law requiring aliens to carry papers.
It is not very different from the state passing laws to help the federal postal service protect the US mail by catching people who violate the laws related to local post offices and mailboxes, which are federal jurisdiction.