Stepping into the increasingly volatile and contentious debate over immigration, the Supreme Court will hear oral arguments tomorrow on how far the state of Arizona can go to prevent employers from hiring undocumented aliens. The case is Chamber of Commerce v. Whiting.

The case involves a 2007 Arizona law that punishes employers who knowingly hire undocumented aliens by suspending or revoking most of their state licenses. The Chamber of Commerce argues that the law is preempted by the federal Immigration Reform and Control Act of 1986 (IRCA).

IRCA prohibits the hiring of undocumented aliens and sets forth procedures employers must follow before hiring someone and the sanctions they will incur for violating the law. Most importantly, IRCA expressly preempts local and state laws creating sanctions (other than through licensing and similar laws).

It is the "licensing and similar laws" clause that is crucial in this case, because the draconian punishment set forth in the Arizona law is the suspension and revocation of "licenses," a term defined so broadly in the statute that it even includes a company’s articles of incorporation.

The Court will also decide whether Arizona can lawfully require employers in the state to use a federally-administered electronic employment verification database called E-Verify – a database that federal law expressly makes voluntary.

Agreeing with the Chamber that the Arizona law is unconstitutional are the Obama Administration and an array of civil rights groups (such as the National Council of La Raza and the Anti-Defamation League).

When the Court issues its ruling next year, it may give clues on how it might rule on Arizona’s more recent "your papers please" law, which has yet to work its way up to the Court.