Arizona's law requiring concrete evidence of citizenship before someone may register to vote is preempted by the National Voter Registration Act, ruled the U.S. Supreme Court on Monday.

The 1993 federal law mandates that states "accept and use" a federal registration form which only requires the registrant to attest to citizenship. Arizona required voter registration officials to reject any application, including the federal form, that did not have documentary evidence of citizenship. The court's opinion is here.

"We conclude that the fairest reading of the statute 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," wrote Justice Antonin Scalia for a 7-2 majority in Arizona v. Inter Tribal Council of Arizona.

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."

Justices Clarence Thomas and Samuel Alito Jr. wrote separate dissents. 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."

"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, MALDEF vice president of litigation and lead counsel for the voters who challenged the Arizona law. "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."

Also on Monday, the court issued a ruling in the closely watched "pay-for-delay" pharmaceutical case Federal Trade Commission v. Actavis. By a 5-3 vote, the court ruled that agreements between brand and generic companies that involve cash payments in exchange for not producing generic versions can be anticompetitive under antritrust laws.

In Maracich v. Spears, the court ruled 5-4 that an attorney's solicitation of potential clients is not a valid purpose under federal law for obtaining state drivers' records.

In a Miranda-related Fifth Amendment case Salinas v. Texas, the court ruled 5-4 that in most cases, a suspect must invoke his or her right to remain silent during a police interrogation in order to benefit from the privilege.

The high court in Alleyne v. United States split 5-4 in deciding that a defendant's "brandishing of a firearm" must be proven to a jury before the defendant can be exposed to a higher mandatory minimum sentence. The court will return to the bench Thursday to hand down more opinions.

Tony Mauro contributed to this report. Contact Marcia Coyle at mcoyle@alm.com. This story originally appeared on Blog of Legal Times.