Yesterday, the Supreme Court held in Chamber of Commerce v. Whiting that the controversial Arizona law on illegal immigration–the Legal Arizona Workers Act of 2007–was not preempted by federal immigration laws. The federal Immigration Reform and Control Act (IRCA) bars employers from employing individuals who are not authorized to work in the United States. In doing so, IRCA limits states ability to regulate such conduct. States may not impose civil or criminal sanctions on employers who employ unauthorized workers, except through licensing and similar laws. Further, federal law permits, but does not require, employers to use E-Verify, an internet-based system that allows an employer to verify a workers work authorization status. The issue before the Court in Whiting was whether the Legal Arizona Workers Act was inconsistent with these federal immigration laws. A majority of the Court held that it was not.

The Legal Arizona Workers Act of 2007 is one of many statutes recently enacted by the states to limit employment of unauthorized aliens. It allows the Arizona state courts to suspend or revoke the licenses necessary to do business in that state if an employer knowingly or intentionally employs an unauthorized alien. Further, the statute requires all employers in the state to verify employment eligibility using the E-Verify system. The U.S. Chamber of Commerce, along with other business and civil rights organizations, brought suit in federal court, alleging that the law was expressly or impliedly preempted by federal immigration law. The district court held that the Arizona law was not preempted, and the Court of Appeals agreed.