Two Democratic senators say nine states are violating federal law with their mail-in voter registration deadlines for the November election, potentially disenfranchising thousands of people by blocking applications as many as three days earlier than other states.

U.S. Sens. Charles Schumer of New York and Patrick Leahy of Vermont asked the U.S. Election Assistance Commission to intervene and work with election officials in those states to ensure compliance with the National Voting Rights Act. The states cited in their letter Thursday are Alaska, Arizona, Arkansas, Hawaii, Mississippi, Rhode Island, South Carolina, Utah and Washington.

“The right to vote is too precious to have something so simple to fix potentially prevent so many Americans from participating in the upcoming Election,” the senators wrote.

The calendar appears to be the culprit.

The deadline for registering by mail under federal law — 30 days before the election — falls on a Sunday this year. The next day happens to be Columbus Day, when there will be no postal service, preventing registrations from being postmarked. All other states have adjusted their deadlines to account for the long holiday weekend, accepting registration applications postmarked by Tuesday, Oct. 11.

Utah is among them, despite being cited in the senators’ letter, said Mark Thomas, the state’s director of elections. State law says nearly all registration deadlines must be moved forward if the deadline falls on a Sunday or holiday, and that’s what Utah has done for this fall’s general election, he said.

Election Assistance Commission spokesman Bryan Whitener said the agency is reviewing the senators’ request.

This year is the first presidential election in which a key enforcement provision of the Voting Rights Act is no longer in effect, and voting rights groups have been aggressively calling attention to any potential for disenfranchisement.

Four of the nine states with the earlier registration deadlines were previously required by a section of the Voting Rights Act to obtain U.S. Justice Department approval before changing voting procedures.

A 2013 ruling by the U.S. Supreme Court set aside the preclearance requirement, opening the way for a wave of new voting laws. Fourteen states have new restrictions on voting or registration in place this year. Experts say the potential for voter confusion is high as courts block or strike down some provisions while upholding others.

The voter registration deadlines cited by the senators apply only to applications that are mailed in. All these states also offer in-person registration, although their rules vary and may require more effort or limit the voter’s choices. Rhode Island offers same-day registration on Election Day, but limits these voters to ballots only for president and vice president.

Still, the number of people mailing in applications can be significant. During the 2012 presidential election, at least 55,000 people in New York state were registered to vote after applying on the last possible day, according to data collected by the state Board of Elections and provided by Schumer’s staff. The number was nearly 39,000 for the same election in Washington state.

Rhode Island officials said they were surprised to hear about the senators’ letter; they thought they were meeting the 30-day requirement by requiring postmarks no later than Sunday the 9th. Officials there and in Alaska said the deadline would not be changed. Carol Thompson with Alaska’s Division of Elections noted that Columbus Day is not a state holiday and state offices would be open.

In Washington state, Secretary of State Kim Wyman emailed local election officials earlier this week recommending they honor an Oct. 11 postmark for applications, and on Friday said that all had agreed to do so. Arkansas election officials said despite the state’s Oct. 10 deadline, applications postmarked Oct. 11 would be accepted.

The issue has been contentious in Arizona, a state previously covered under the Voting Rights Act. Democrats asked the secretary of state to change its deadline of Monday, Oct. 10.

Secretary of State Michele Reagan, a Republican, has no plans to do so, said her spokesman, Matt Roberts. One reason, he said, is that pushing back the deadline would cut into the time counties have between processing registrations and early ballots.

“Without legislation, it’s difficult to deal with some of this stuff because you’re really opening a Pandora’s box of problems,” Roberts said. “We’re still confident that we made the right decision.”

He said Reagan intends to ask lawmakers next year to pass legislation that would call for the early voting deadline to be postponed a day if it falls on a holiday. In the meantime, the office is encouraging people to register electronically and to take action before the deadline.

Associated Press writers Becky Bohrer in Juneau, Alaska; Rachel La Corte in Olympia, Washington; Claudia Lauer in Little Rock, Arkansas; Matt O’Brien in Providence, Rhode Island; Michelle L. Price in Salt Lake City; and Terry Tang in Phoenix contributed to this report.

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