Justices appear divided on Arizona voting law Arizona voters in 2004 passed a requirement that applicants provide additional proof beyond that statement. The U.S. Court of Appeals for the 9th Circuit ruled against the state, saying Arizona could not add requirements to the federal form. The state-by-state battle over who is eligible to vote, what kind of identification or proof may be required and even the hours of voting prompted a host of legal battles leading up to the 2012 elections. In general, Republicans proposed new restrictions as necessary to combat voter fraud, while Democrats said they would harm minorities and the poor who do not have easy access to the required credentials. The oral arguments Monday hardly reflected those incendiary partisan battles--there was an extended discussion about whether "may require only" really means "shall require only." Still, a ruling for Arizona could open the door for states to add requirements to the federal registration form, and the issue seemed to split the court along familiar ideological lines. Arizona Attorney General Thomas C. Horne (R) told the court that the National Voter Registration Act required the development of the federal form that applicants may mail in to register to vote, but it did not mean to serve as a limitation on what the states could require. "It is the burden of the states to determine the eligibility of the voters," Horne said, adding that Congress did not specifically tell states not to demand citizenship proof. "Congressional silence should not disable states from taking sensible precautions to exclude noncitizens from voting," he said. He immediately ran into trouble from liberal justices Ruth Bader Ginsburg, Sonia Sotomayor and Elena Kagan. Ginsburg said Congress was not silent about citizenship--it decided that a sworn statement subject to perjury charges was sufficient. So it's not as though the federal form didn't relate to citizenship. It did," Ginsburg said. "And it said this is the way we deal with citizenship. Then Arizona adds something else. Justice Anthony M. Kennedy, who might be in a pivotal position given the split reactions of his colleagues, asked Horne if Arizona could add other requirements. When Horne said yes, if they were consistent with the objectives of the act, Kennedy said it then seemed to him that the federal form "is not worth very much." On the other hand, Kennedy said the appeals court used a test that "ignores the proposition that the state has a very strong and vital interest in the integrity of its elections, even when those, and perhaps especially when those are elections of federal officials." Justice Sandra Day O'Connor, who in retirement hears cases in the lower courts and was part of a panel ruling against Arizona in this one, watched Monday's proceedings from the front row. The Arizona law is being challenged by, among others, the League of Women Voters, the Mexican American Legal Defense and Educational Fund and the Inter Tribal Council of Arizona. Their lawyer, Patricia A. Millett, said Congress's intent was to reform a system where "40 percent of eligible voters were not registered, because state procedures and burdens were standing as an obstacle." "Enclosing your driver's license number is that immense barrier, right?" asked Justice Antonin Scalia, referring to one of the ways applicants could satisfy Arizona's proof of citizenship requirement. He said it should be "no problemo" for the state to require what the federal form lacks. Millett responded that said only driver's licenses acquired after 1996 would work. She said the district court found more than 31,000 people were rejected from registration because of Arizona's law--11,000 of whom were eventually registered and that Horne acknowledged there was no reason to believe the other 20,000 were ineligible. Justice Samuel A. Alito Jr. said it was a "crazy system" for Arizona to be able to require certain information under its own registristration procedures but not the federal form. But Deputy Solicitor General Sri Srinivasan, representing the Obama administration and defending the federal law, said the purpose of the law would be defeated if the form "set a floor, but then each of the 50 states could superimpose whatever additional requirements they wanted." The case is Arizona v. Inter Tribal Council of Arizona .