n May 26, 2011, the United States Supreme Court issued a 5-3 decision in Chamber of Commerce v. Whiting upholding the Arizona Legal Workers Act (“the Act”). The Act provides that the business licenses of employers who knowingly or intentionally employ unauthorized aliens may be, and in certain circumstances must be, suspended or revoked. The law also requires that all Arizona employers use E-Verify. The Court held that neither of these provisions was preempted by federal immigration law.

This case arose when the Chamber of Commerce of the United States and various business and civil rights organizations filed a federal pre-enforcement suit against those charged with administering the Act in the Arizona District Court, arguing that the Act was preempted by federal immigration law. The District Court held that the Act was not preempted by federal law, and the decision was affirmed by the Ninth Circuit.