Associated Press

WICHITA -- A decision on whether states have a constitutional right to require proof-of-citizenship documentation for their residents who register to vote using a national form now is in the hands of a federal judge in a case with broad implications for voting rights.

U.S. District Judge Eric Melgren listened to arguments from attorneys Tuesday, but did not immediately rule. He did not say when he would issue his written decision.

The lawsuit filed by Kansas and Arizona seeks to force the U.S. Election Assistance Commission to include the heightened requirements only for their residents. However, the Justice Department has argued changing the requirements on the federal form for those two states would in essence affect nationwide policy, because it might encourage other states to seek increased proof of citizenship to register to vote in federal elections.

Both states require voters to provide a birth certificate, passport or other proof of U.S. citizenship when registering to vote. Those who register using the federal form sign only a statement under oath they are U.S. citizens.

In December, Melgren sent the issue back to the EAC for final agency action, but said he had "serious reservations" about the federal government's power to rule on the voter registration issue. His tough questioning of attorneys for the Justice Department and voting rights groups during Tuesday's hearing frequently returned to that state rights issue.

"My decision comes down constitutionally to who gets to decide what is necessary," Melgren said.

The EAC denied the states' requests last month to change the federal form, finding heightened proof-of-citizenship requirements likely would hinder eligible citizens from voting in federal elections.

The dispute stems from a U.S. Supreme Court ruling in June that barred states -- Arizona in that particular case -- from refusing to accept the national voter registration form.

But Melgren told attorneys Tuesday he didn't see a clear statement in that Supreme Court opinion signaling the agency has the authority to be the decision-maker for the states.

Kansas Secretary of State Kris Kobach has championed his state's proof-of-citizenship law as a way to prevent noncitizens from voting, particularly those in the U.S. illegally. Critics said incidents of noncitizens registering to vote are extremely rare, and such Republican-backed proof-of-citizenship laws hurt voter registration efforts and disenfranchise voters from certain groups that tend to vote Democrat, including minorities, college students and the elderly.

Kobach, a Republican, argues states have the sovereign right to maintain their voter rolls and the federal voter registration form should therefore be tailored to the requirements of each state. He asked the court for a declaration that the agency's refusal to change the federal forms violates the state's constitutional rights, and to order the agency to include such proof-of-citizenship language on the form for Kansas and Arizona residents.

The Justice Department, which is representing the EAC in the lawsuit, contends there are no constitutional dimensions to the case, even though Kobach is inviting the court to relitigate issues that already have been settled in the Supreme Court case. He said the agency is not contesting the state's right to set voter qualifications in their own elections.

When Congress enacted the National Voter Registration Act, it considered and ultimately rejected such a documentation requirement, said DOJ civil rights attorney Bradley Heard. Additional documentation is unnecessary because safeguards already exist that allow election officials to determine applicants' citizenship status.