Arizona v. United States: A Limited Role for States in Immigration Enforcement

On June 25, 2012, the Supreme Court issued its much-anticipated decision in Arizona v. United States, ruling that some aspects of an Arizona statute intended to deter unlawfully present aliens from remaining in the state were preempted by federal law, but also holding that Arizona police were not facially preempted from running immigration status checks on persons stopped for state or local offenses. In reaching these conclusions, the Supreme Court made clear that opportunities for states to take independent action in the field of immigration enforcement are more constrained than some had previously believed. In recent years, several states and localities have adopted measures intended to deter the presence of unauthorized aliens within their jurisdiction. An Arizona measure enacted in 2010, commonly referred to as S.B. 1070, arguably represents the vanguard of these attempts to test the legal limits of greater state involvement in immigration enforcement. The major provisions of S.B. 1070 can be divided into two categories: (1) those provisions seeking to bolster direct enforcement of federal immigration law by Arizona law enforcement, including through the identification and apprehension of unlawfully present aliens; and (2) those provisions that criminalize conduct which may facilitate the presence of unauthorized aliens within the state. Before S.B. 1070 was scheduled to go into effect, the Department of Justice (DOJ) brought suit to preliminarily enjoin many (but not all) of S.B. 1070's provisions, arguing that they were likely preempted by federal immigration law and therefore unenforceable under the Supremacy Clause. The district court granted the DOJ's motion to preliminarily enjoin four of the Arizona law's provisions, and the injunction was upheld by the U.S. Court of Appeals for the Ninth Circuit. The Supreme Court thereafter granted certiorari to review the case. The eight Justices who decided the case (Justice Kagan recused herself) were asked only to consider whether the four enjoined provisions of S.B. 1070 were facially preempted by federal law. They did not consider other constitutional challenges to the validity of the Arizona law, including claims that enforcement of S.B. 1070 could lead to impermissible racial profiling. A majority of the Court found that the Arizona measure's criminal sanctions for alien registration violations and upon unauthorized aliens who seek employment in the state were preempted by federal law. The Court also ruled invalid a provision authorizing the warrantless arrest of aliens who have criminal offenses that constitute grounds for removal under federal immigration …