In December 2010, the U.S. Supreme Court heard oral arguments in Chamber of Commerce of the United States v. Whiting. At issue was an Arizona law allowing the state to revoke the business licenses of employers who knowingly hired unauthorized immigrants. Whiting was the first in a series of Supreme Court cases involving immigration-related laws at the state level, all of them passed by the state of Arizona. The most prominent of these laws was SB 1070, a state enforcement law passed earlier that year, eliciting a lawsuit from the Obama administration and eventually leading to the Arizona v. United States decision. Although Whiting was less well-known, the stakes were nevertheless very high – not only for workers who might be affected by Arizona's law, but also for employers, labor unions, other states, and even the federal government.

Several disparate groups filed briefs in the Supreme Court supporting the Chamber of Commerce's campaign against the law. The Chamber represented the concerns of employers who were worried that, if Arizona's law were allowed to stand, they would need to contend with a proliferation of individual state and local laws on employer verification, each with its own set of requirements. In addition to the Chamber of Commerce as petitioner, other business organizations filed an amicus brief, arguing that a “patchwork of state and local laws undermines Congress's intent to establish a comprehensive and uniform national framework that limits the imposition of undue burdens on businesses.” The federal government also had a keen interest in the case and it, too, filed an amicus brief in support of the petitioner, arguing that federal law, especially the 1986 Immigration Reform and Control Act (IRCA), left no room for laws like Arizona's to take hold. Indeed, another amicus brief by former members of Congress, including Romano Mazzoli who helped author the 1986 law, argued that Congress intended to expressly preempt the ability of states to impose employer sanctions, and that it intended any exception for state licensing laws to be interpreted narrowly. Finally, labor groups and immigrant advocacy organizations were also concerned about heightened employer verification requirements, arguing that Arizona's law threatened to upset the careful balance struck by federal law, between the goals of deterring unauthorized employment, on the one hand, and avoiding employee discrimination and national origin profiling, on the other.