Arizona Immigration Law Mostly Preempted

The Supreme Court has ruled that most of SB1070, the Arizona law concerning immigration, is preempted by federal law.  Field preemption applies to section 3 of the Arizona law; obstacle conflict preemption knocks out the remainder except for section 2B, which is the requirement that law enforcement officers check the immigration status of detainees or arrestees.  It's too soon to determine whether section 2B stands as an obstacle to federal law.  Here's the opinion.