If Congress does not act on immigration reform and federal enforcement efforts cannot curb the large U.S. population of unauthorized foreign nationals, can states take matters into their own hands? This question has occupied state legislatures, federal courts and the public discourse for several years now. On June 25, the Supreme Court weighed in, ruling in Arizona v. United States that S.B. 1070, a controversial state immigration enforcement statute that sought to criminalize unlawful presence and empower state and local police to check immigration status and conduct warrantless arrests of those suspected of deportable offenses, was largely preempted by federal immigration law.1
The courtthough sympathetic to the plight of states frustrated by Congress’ legislative inactivity and limited federal support in dealing with the undocumented populationcame down forcefully on the side of the federal government and admonished that states “may not pursue policies that undermine federal law.” This article will review the court’s decision and its important holdings on the supremacy of the federal immigration regime.
