Justices appear divided on Arizona voter ID law

Washington — An Arizona law requiring would-be voters to show proof of U.S. citizenship seemed to divide Supreme Court justices Monday in a case important to many states that want to stiffen their own voting standards.

Conservative justices sounded sympathetic to Arizona's proof-of-citizenship requirement, while more liberal justices suggested the measure might conflict with a 1993 law passed by Congress called the National Voter Registration Act. The eventual ruling will define when federal law pre-empts state efforts, a legal determination that accompanies political controversies ranging from illegal immigration to allegations of voter suppression.

"Many people don't have the documents that Arizona requires," Justice Sonia Sotomayor noted pointedly at the start of the hourlong oral argument Monday.

Sotomayor and Justice Elena Kagan, a fellow Obama administration appointee, pushed back most vigorously against the Arizona law. From the other side, though, Republican appointees, including Chief Justice John Roberts Jr. and Justice Samuel Alito, pressed questions seemingly supportive of Arizona's actions.

"The state has a very strong and vital interest in the integrity of its election ... perhaps especially when those are elections of federal officials," said Justice Anthony Kennedy, a frequent swing vote on close cases, adding that a lower appellate court "did not give sufficient weight to that interest" when it struck down Arizona's law.

Beyond the immigration debate, the Arizona case also arises amid increasingly aggressive nationwide efforts to impose photo identification or other requirements on voters. These broader stakes were underscored by numerous friend-of-the-court briefs.

Kansas Secretary of State Kris W. Kobach, who has made his mark nationally as a border-security hardliner, filed a brief supporting the Arizona law. Kansas has imposed its own proof-of-citizenship requirements, effective this year. Separately, Kansas joined Texas, Georgia and three other states in filing a similar brief supporting Arizona, arguing states' "control over elections will be diminished" if the court strikes down Arizona's law.