In this case registered voters in Arizona and voters' rights groups including Project Vote challenged Proposition 200, an Arizona law that imposed proof of citizenship and voter ID requirements, which Plaintiffs argued disparately impact Latinos. Plaintiffs sought a Preliminary Injunction preventing the enforcement of these voter identification requirements.

The district court denied Plaintiffs' Motion for Preliminary Injunction on September 11, 2006. On August 20, 2008 the district court issued a judgment in favor of the defendants. After having the Supreme Court deny a preliminary injunction prior to the November 2010 federal elections, the plaintiffs took the case to trial. The plaintiffs appealed to the court of appeals and on October 26, 2010, the court reversed the district court’s decision on the issue of requiring proof of citizenship.