Arizona again will be in the national spotlight regarding illegal immigration when the U.S. Supreme Court hears arguments Wednesday on whether the state can punish employers who knowingly hire undocumented workers.

At issue is the 2007 Legal Arizona Workers Act, commonly called the employer-sanctions law, which was among the first in which a state tried to assume control of what previously had been strictly a federal function. The landmark has withstood challenges in U.S. District Court and the 9th U.S. Circuit Court of Appeals, which have said the law is constitutional.