People wait in line to vote in the primary at the Environmental Education Center on March 22 in Chandler, Ariz. (David Kadlubowski/AP)

Nine states have shortened the time still allowed for voters to register for the November election, in some cases designating as the last day to register the Columbus Day federal holiday when government offices are closed.

Democratic Sens. Charles E. Schumer (N.Y.) and Patrick J. Leahy (Vt.) said that the states — Alaska, Arizona, Arkansas, Hawaii, Mississippi, Rhode Island, South Carolina, Utah and Washington — could be in violation of the National Voter Registration Act, which requires states to accept registration forms if they were postmarked 30 days before Election Day, because their deadline is on a weekend day without postal service or on a holiday.

In a Sept. 30 letter to the federal Election Assistance Commission, the senators urged the EAC to take action to ensure that the states change ­voter-registration deadlines that fall before Oct. 11 to comply with federal law. The EAC was established in 2002 to help states run elections and to disseminate the federal online voting form.

“We know that every day of voter registration in the month before the election is an opportunity for hundreds of thousands of Americans across the country to get registered to vote or update their voter registration information,” the senators wrote.

Chairman Thomas Hicks said in an interview that the EAC cannot require the states to change their voter-registration dates.

“There’s not much we can do other than urge the states to change it,” said Hicks, who sent the senators’ letter to officials in the nine states. “We don’t have the authority to force them to change anything.”

On Friday, EAC officials held a conference call with state leaders and election directors in some of the states.

In Arizona, House Minority Leader Eric Meyer (D) sought a formal opinion last month from the state attorney general, saying that “time is of the essence.”

“Arizona law provides that when the day to perform a function falls on a holiday, the deadline is extended to the next business day,” he wrote. “The deadline should be October 11th, not October 10th.”

More than 40 percent of voter registration applications in Arizona are submitted through the mail or in person at Motor Vehicle Division offices, Meyer said, and all U.S. post offices and MVD offices will be closed Columbus Day.

But Deputy Solicitor General Dominic E. Draye, citing “the likelihood of imminent litigation regarding this question,” replied that the attorney general would support Secretary of State Michele Reagan (R), who decided on the Columbus Day deadline.

“Competing legal principles reflect a lack of clarity in the law that leaves room for the exercise of discretion on the part of the Secretary of State,” Draye wrote.

Spencer G. Scharff, the state Democratic Party’s voter protection director, said, “We are not aware of any imminent litigation on this issue.”