here - I found something very relevant..
Muehler v. Mena, 544 U.S. 93 (2005), was a unanimous decision by the United States Supreme Court, which held that the Fourth Amendment to the United States Constitution allows
1. detention of a search subject in handcuffs while a search is being conducted,
2. and that it does not require officers to have an independent reasonable suspicion before questioning a subject about their immigration status.
and the Arizona law DOES require the cops to have reasonable suspicion.. so if anything, it's stricter than the federal law..