The U.S. Supreme Court will hear a case that challenges the Legal Arizona Workers Act of 2007 -- the state's employer-sanctions law that allows authorities to go after the business licenses of employers that knowingly hire illegal immigrants. Business and civil rights groups, backed by the Obama administration, challenged the law as a clear and unconstitutional attempt to pre-empt federal authority. But some judges at the 9th U.S. Circuit Court of Appeals upheld the constitutionality of the law. "The power to regulate the employment of unauthorized aliens remains within the states' historic police powers," a judge noted.