Filed: May 17, 2010

On May 17, 2010, the ACLU of Arizona joined with other legal groups, including the ACLU Immigrants’ Rights Project, National Immigration Law Center, Mexican American Legal Defense and Education Fund, Asian Pacific American Legal Center, National Day Labor Organizing Network, NAACP and Munger Tolles to file a constitutional challenge to the anti-immigrant state law, SB 1070.  In addition to preemption concerns under the Supremacy Clause, Plaintiffs argue that the Arizona law invites racial profiling against people of color by law enforcement in violation of the equal protection guarantee and prohibition on unreasonable seizures under the 14th and Fourth Amendments, and infringes on the free speech rights of day laborers and others in Arizona.

The plaintiffs sought a preliminary injunction to prevent all or portions of the law from being implemented on the July 29, 2010 effective date. On July 22, 2010 oral argument was heard by Judge Susan Bolton, in both the ACLU case and in the case brought by the U.S. Department of Justice, which also sought to enjoin the law as being preempted by federal laws and actions. On July 28, 2010, ruling in the DOJ case, the judge agreed with the arguments of the ACLU, and the federal government, and enjoined the key provisions of SB 1070 from going into effect until fully litigated. Arizona appealed the decision to the Ninth Circuit Court of Appeals and oral argument took place on November 1, 2010. With the ACLU participating as amicus, the Ninth Circuit Court of Appeals affirmed this important result and the State sought interlocutory review by the U.S. Supreme Court.

In February 2012, plaintiffs’ renewed motion for a preliminary injunction was granted, enjoining the provisions criminalizing solicitation for day labor work. Arizona appealed that decision to the Ninth Circuit Court of Appeals but the trial court decision was affirmed. Additionally, in another important ruling, the Ninth Circuit affirmed Judge Bolton’s injunction on the provision of the law criminalizing “harboring” or transporting persons who are not lawfully in the country. Further, on March 4, 2013, the Ninth Circuit upheld the district court’s injunction against the provisions of SB1070 regarding day laborers. Thus, the majority of the provisions of this draconian law have been permanently enjoined and have not gone into effect.

In December 2011, the U.S. Supreme Court agreed to review the injunction granted by Judge Bolton on the key provisions of SB 1070, and upheld by the Ninth Circuit, in the federal government’s case, U.S. v. Arizona. The case was argued before the Supreme Court in April 2012, and an opinion issued on June 25, 2012. The Supreme Court upheld most of Judge Bolton’s ruling but, unfortunately, reversed and remanded on the key “show me your papers” provision. The Court found that it was not on its face unconstitutional, but, depending how it was implemented, the law may not survive.

After the U.S. v. Arizona opinion was issued, the Valle Del Sol plaintiffs filed another challenge to the remainder of SB 1070, arguing the discriminatory intent of the legislators, especially former state Senator Russell Pearce, in drafting and enacting the law. Plaintiffs and defendants filed motions for summary judgment, which were decided on September 4, 2015. In her decision, Judge Bolton ruled in favor of plaintiffs by permanently enjoining the day labor provisions of the law but ruled against plaintiffs on remaining counts including the “show me your papers” provision of the law. 


Pro Bono Law Firm(s)

National Immigration Law Center


United State Supreme Court



Case number

CV 10-1061