In July 2010, the U.S. Department of Justice won a key victory when U.S. District Judge Susan R. Bolton blocked the enforcement of the most controversial parts of Arizona’s law, just days before the law was to go into effect. The state appealed to the U.S. Court of Appeals for the Ninth Circuit, which in a 2-1 ruling, upheld the injunction.

On September 30, 2010, CAC filed a brief in the Ninth Circuit in support of the federal government in this case. As we explained in our brief, Arizona’s controversial law, which seeks to supplant the federal government in enforcing immigration laws in Arizona, is in direct conflict with the text of the U.S. Constitution, the document’s drafting history, and its federalist structure.

On April 11, 2011, the Ninth Circuit, in a 2-1 ruling, upheld Judge Bolton’s injunction, holding that the federal government was likely to succeed on the merits of its claim that the blocked provisions of the state law are unconstitutional because they inappropriately interfere with the federal government’s power to regulate immigration and naturalization issues. Both Judge Paez’s opinion for the court and Judge Noonan’s concurrence appropriately emphasize that the federal government’s powers are particularly sweeping when it comes to foreign affairs. Indeed, as we explained in CAC’s brief, Congress’ constitutional power to make a “uniform rule of naturalization” is one of the few places where the Constitution makes absolutely clear that the federal government’s power is exclusive. Read our statement praising the Ninth Circuit’s decision, here.

On December 12, 2011, the Supreme Court granted review of the case.

On March 26, 2012, CAC filed a brief in the Supreme Court in support of the federal government. As we explained in our brief, Arizona’s controversial law, which seeks to supplant the federal government in enforcing immigration laws in Arizona, is in direct conflict with the text of the U.S. Constitution, the document’s drafting history, and its federalist structure. Congress’ constitutional power to make a “uniform rule of naturalization” is one of the few places where the Constitution makes absolutely clear that the federal government’s power is exclusive.

On April 25, 2012, the Court heard oral arguments.

On June 25, 2012, by a vote of 5-3 (Justice Kagan recused), the Court ruled that three of the four challenged provisions were preempted because they either operated in areas solely controlled by federal policy, or they interfered with federal enforcement efforts, including SB 1070’s sections making it a crime to be in Arizona without legal papers, making it a crime to seek employment in the state, and allowing police to arrest individuals who had committed crimes that could lead to their deportation. The Court did not preempt the controversial “show me your papers” provision, which requires police to arrest and hold anyone they believe has committed a crime and whom they think is in the country illegally, holding them until their immigration status could be checked with federal officials— but made clear that the provision could be subject to later challenges in lower courts.

Read the decision, authored by Justice Anthony Kennedy, as well as the dissents, here.

For an in-depth analysis of the case, and to learn more about CAC’s involvement, visit our blog Text & History.