The U.S. Supreme Court on Monday struck down an Arizona law that required residents to provide proof of citizenship when using federal forms to register to vote.

Civil rights groups and others concerned about an array of new state voting restrictions immediately hailed the 7-2 decision in Arizona v. Inter Tribal Council of Arizona.

"Today's decision sends a strong message that states cannot block their citizens from registering to vote by superimposing burdensome paperwork requirements on top of federal law,” stated Nina Perales, lead counsel for the voters who challenged the Arizona law and vice president of litigation for MALDEF — the Mexican American Legal Defense and Educational Fund. "The Supreme Court has affirmed that all U.S. citizens have the right to register to vote using the national postcard, regardless of the state in which they live."

The National Voter Registration Act of 1993, dubbed the motor voter law for its use in voter registration drives, allows individuals to register to vote using a simple, uniform, mail-in postcard form. The federal law mandates that states "accept and use" the form which only requires the applicant to attest to citizenship under penalty of perjury.

In 2004, Arizona voters approved Proposition 200 which requires state election officials to reject every voter registration application—including a properly filed federal form — that lacks certain documentary evidence of citizenship. The required documentation includes Arizona driver's licenses issued after 1996, U.S. birth certificates, and passports.

A group of nonprofit organizations, led by the Inter Tribal Council of Arizona, and individual Arizona residents filed separate lawsuits seeking to enjoin the voting provisions of Proposition 200. They claimed that between the time of the implementation of Proposition 200 in 2005 and the trial in 2008, more than 30,000 voter registrants were rejected in Arizona because they did not include the additional documentation required by Proposition 200. Eighty percent of the rejected registrants were non-Latino and more than 90 percent were born in the United States.

A panel of the U.S. Court of Appeals for the Ninth Circuit held that the documentary proof of citizenship requirement conflicted with the text, structure and purpose of the federal law.

In the Supreme Court, Arizona argued that the federal law's mandate that states "accept and use" the federal form merely requires that a state receive the form willingly and use it as one element in its dealings with a prospective voter.

Justice Antonin Scalia, writing for the 7-2 majority, disagreed with the state's interpretation of those words, explaining that to read "accept" merely to denote willing receipt "seems out of place in the context of an official mandate to accept and use something for a given purpose." He also said Arizona's interpretation was difficult to reconcile with neighboring provisions of the federal law.

He also noted that under the federal law, states retain flexibility to develop their own registration forms. But the federal form provides a "backstop" in that it guarantees, regardless of state procedural hurdles, that a simple means of registering to vote in federal elections, will be available, he said.

"Arizona's reading would permit a State to demand of Federal Form applicants every additional piece of information the State requires on its state-specific form," he wrote. "If that is so, the Federal Form ceases to perform any meaningful function, and would be a feeble means of 'increasing the number of eligible citizens who register to vote in elections for Federal office.'"

The "fairest reading" of the federal law, he added, is that " a state-imposed requirement of evidence of citizenship not required by the Federal Form is 'inconsistent with' the NVRA's mandate that States 'accept and use' the Federal Form."

However, Scalia noted that although the federal law prohibits states from demanding additional information beyond what is required by the federal form, "it does not preclude States from 'denying registration based on information in their possession establishing the applicant's eligibility.' The NVRA clearly contemplates that not every submitted Federal Form will result in registration."

And, he added, states may ask the Elections Assistance Commission to alter the federal form to include information that a state believes is needed to determine eligibility. If the commission declines, the state can challenge that rejection in a lawsuit under the Administrative Procedure Act.

Justice Anthony Kennedy wrote an opinion concurring in part and concurring in the judgment in which he took issue with the majority's conclusion that the presumption against preemption does not apply because the source of congressional authority for the motor voter law is the Constitution's elections clause.

Justices Clarence Thomas and Samuel Alito Jr. wrote separate dissents. Thomas, with a rare footnote citation to Bush v. Gore, said the history and plain text of the voter qualifications clause in the Constitution and the 17th Amendment authorize states to determine voter qualifications in federal elections and that includes the power to determine whether those qualifications are satisfied.

Thomas said that he would interpret the federal law as "only requiring Arizona to accept and use the form as part of its voter registration process, leaving the State free to request whatever additional information it determines is necessary to ensure that voters meet the qualifications it has the constitutional authority to establish."

And Alito wrote, "The NVRA does not come close to manifesting the clear intent to pre-empt that we should expect to find when Congress has exercised its Elections Clause power in a way that is constitutionally questionable." He said he would hold that a state "accepts and uses" the federal form "so long as it uses the form as a meaningful part of the registration process."

Jon Greenbaum, chief counsel to the Lawyers Committee for Civil Rights Under Law, counsel of record for the Inter Tribal Council, said, "It took seven years and a series of appeals but now Arizona has to follow the law. The Supreme Court correctly interpreted Congress' clear intent. Congress saw the federal form as a stand-alone, uniform document that simplifies voter registration for citizens, not a document that gives the states license to add burdensome requirements."

Patricia Millett, head of the Supreme Court practice at Akin Gump Strauss Hauer & Feld argued the case on behalf of the Inter Tribal Council. She received support at argument from former Deputy Solicitor General Sri Srinivasan. Attorney General Thomas Horne represented Arizona.

Marcia Coyle can be contacted at mcoyle@alm.com.