Civil rights groups, voting rights advocates, clergy and the state NAACP are among those protesting the restriction of early voting hours in the battleground state of Ohio, which allowed voters to cast their ballots during evenings and weekends before the 2008 Election.

This could disproportionately impact African-American voters, who are more likely to use in-person early voting to cast their ballot, and are more numerous in the urban counties affected.

“It’s just another example of voter suppression,” said Sybil Edwards McNabb, president of the Ohio Conference NAACP, which has spoken out against the move.

The American Civil Liberties Union sent a letter to Ohio Secretary of State Jon Husted on Monday, urging him to expand access statewide. And the African American Ministers Leadership Council, issued a press release condemning the reduced opportunities for early voting.

“There are politicians doing the unthinkable: they are making it harder for their constituents to exercise our constitutionally guaranteed right to vote,” the Rev. Dr. Tony Minor of Cleveland said in the release, issued through the national rights group People For the American Way.  “Once again, these suppression efforts are aimed directly at African Americans in swing states.”

County election boards, which are each composed of two Republican and two Democrat members, have deadlocked in several of the state’s most populous – and traditionally Democratic – counties. The Democrats tried to extend available early voting hours, only to find themselves blocked by their Republican counterparts. But in other counties where Republican voters dominate, the boards have voted to extend their hours.

Husted, a Republican, can intervene to break a tie on a deadlocked board. In each case, he’s decided to restrict early voting hours to the same hours the local board of elections is usually open. Most of the offices are open between 8 a.m. and 5 p.m., but some close as early as 4 p.m.

Husted has since said that due to the controversy, he might mandate limited early voting hours statewide.

Ohio Democratic Party spokesman Jerid Kurtz said that the restrictions a partisan move intended to reduce the number of Democratic votes by making the process less accessible.

“Shouldn’t we be devoted and dedicated to people being able to vote when they can and not turning them away from the polls?” said Kurtz.

Franklin, Cuyahoga, Lucas and Summit Counties house four of the state’s largest cities: Columbus, Cleveland, Toledo and Akron. All of those counties went to President Barack Obama in the 2008 election, and all are now facing fewer opportunities for early voting than they did that year. Hamilton County, home to the city of Cincinnati, will decide its voting hours this Thursday.

The sixth-largest county, Montgomery, in which Dayton is located, is the only Democratic-leaning county to have extended its hours. Project Vote’s Election Counsel and Manager for Ohio, Camille Wimbush, said the Montgomery election board’s director told her they made that decision in January, “to avoid the controversy that has now ensued over this issue.”

Husted spokesman Matt McClellan said that Husted is aiming for uniformity, and that some counties don’t have the resources to keep their early voting facilities open beyond normal business hours. He added that “there’s ample time for people to cast their ballot” by mail.

But Keesha Gaskins, Senior Counsel at New York University Law School’s Brennan Center for Justice, said that not everyone considers mail-in ballots a suitable substitution for in-person voting, particularly minority and elderly voters who are worried about whether their vote will be properly counted.

“There is less trust with mail-in ballots” said Gaskins, who is an expert on voting and civil rights. “Lots of times when people are thinking about their vote, they want to hand their ballot to an election official, they don’t want to put it in the mail and hope for the best.”

For the upcoming presidential election, in-person early voting in Ohio begins Oct. 2. It ends at 6 p.m. on Nov. 2, the Friday before Election Day, for all voters except for civilians voting from overseas and families of military members, who have through Nov. 1 to cast an early vote. The Obama campaign, Democratic National Committee and Ohio Democratic Party filed a lawsuit in federal court last month to force the state to offer all voters the opportunity to cast a vote in the final days before the election. A hearing is scheduled for Wednesday, Aug. 15.

Ohio’s 2006 introduction of early voting hours, which included evenings, Saturdays and Sundays up until the day before the election, was supposed to be a way to prevent the excessively long lines that frustrated voters during Election Day 2004. In some districts, people waited past midnight to vote, and many gave up and went home or back to work.

Follow Stephanie Siek on Twitter at @TweetsNotTwits.