On April 25, 2012, the US Supreme Court heard oral arguments in the case of Arizona v. United States. On June 25, 2012, the Court decided the legal fate of Arizona’s highly controversial immigration laws, more commonly referred to as SB 1070. The Court ruled that three sections of the law intruded upon the authority of the federal government, while the most controversial provision was upheld [PDF]. The Arizona law caused nationwide controversy that implicated areas of international relations and public policy and underscored tensions between state and federal governments. While the decision will have an immediate effect on only the Arizona legislation, it will serve as a flashpoint for the modern debate over immigration regulation in the US.

A lack of comprehensive federal reform prompted many states, including Arizona, to pass legislation that purports to enforce federal immigration law. Such laws sought to grant state law enforcement officials expanded powers to identify potential undocumented immigrants, have made it a crime to fail to provide documentation of immigration status, and have attempted to make it more difficult for employers to hire resident and undocumented immigrants. Proponents argue that these measures are required to fully address the growing problem of undocumented immigrants, while opponents have argued that these legislative measures lend legitimacy to open ethnic discrimination.