COLUMBUS (AP) -- It doesn't take much to start a political spat in Ohio, where jockeying for every presidential vote is practically blood sport. The latest pits President Barack Obama's campaign against groups representing military voters, an uncomfortable place for the commander in chief.
At issue is the legality of an Ohio law cutting three days out of the early-voting period for everyone except members of the armed forces and Ohio citizens living overseas. The dispute reaches court today, thanks to what the Obama campaign describes as its first lawsuit anywhere in the nation for the 2012 election.
Put simply, looser rules for early voting are seen by both political parties as an advantage for Obama because they may encourage minorities, young people and other harder-to-reach voters to cast a ballot. Military votes are thought to lean Republican.
As state lawmakers debated changes to election laws, the Ohio Association of Election Officials endorsed the idea of cutting the three final early-voting days, those just before Election Day, contending they needed the extra time over the weekend to prepare for Tuesday voting.
Democrats say it smacks of political manipulation to restrict in-person voting for most people while giving service members extra time to cast a ballot, even if they are not stationed abroad. They want the three days added back for everyone.
"Ohio has arbitrarily decided to turn most, but not all, voters away from open in-person voting locations for no reason at all," attorneys for the Obama campaign write in court filings.
Republicans see a chance to drive a wedge between Obama and parts of the country where the military culture runs deeps. A Gallup poll in August found a 57-35 advantage for Mitt Romney over Obama among veterans.
Romney was fast off the mark when the issue flared, declaring his opposition to the lawsuit against the state's attorney general and top elections official, and his solidarity with the 15 military organizations opposing the legal challenge. "I'll work to protect the voting rights of our military, not undermine them," Romney said in a statement.
Democrats said that veterans, the elderly or infirm, are among those disadvantaged by not having the extra days to vote.
AMVETS, a veterans' advocacy group, and groups representing members of the National Guard, Army, Navy and Marines are among organizations opposing the suit. While keeping their distance from the partisan fray, they worry about the precedent that could be set for military voters around the nation if the federal court here decides they should not be treated differently.
Early-voting rules have been in flux nationally, generally with Democratic leaders striving for a more open regimen and Republicans trying to hold the line or push back. In all, 32 states plus the District of Columbia allow voters to cast an early ballot by mail or in person without having to give a reason. In 2008, about 30 percent of Ohio's total votes -- or roughly 1.7 million -- came in before Election Day.
Of those, Democrats estimate in their lawsuit that 93,000 voted just in the final days. Then, advance voters had until the day before the election, a Monday. Now, early in-person voting is to stop the Friday before Election Day for most.
It's not surprising to see an election lawsuit popping up in Ohio already.
"Ohio is a repeat player in the election litigation business," said Edward Foley, an elections law expert at Ohio State University. "It stands to reason that the candidates are going to care more about the voting rules for a swing state."
Obama won Ohio in 2008. Romney is expected to make a strong play for it in November.
Three days of in-person voting before Election Day were eliminated for most Ohio voters after a series of contentious election law changes cleared the state's Republican-controlled Legislature and Republican Gov. John Kasich signed them into law.
The Obama campaign has a network of people handling voter protection issues in states in a more informal way. For instance, the campaign has worked with state Democratic parties in Florida and Colorado to seek records in cases where the state claims to have a list to purge noncitizens from the rolls. But the campaign hasn't filed other lawsuits in state or federal courts.
"We don't resort to lawsuits as a matter of policy," said Bob Bauer, general counsel of Obama for America. Lawsuits are complicated, expensive, time-consuming and confusing, he added.
But Bauer said: "There isn't any other way to solve the problem in Ohio outside this federal court system. There's nothing we can do because the decision has been made, and that's how the state is preparing for the election."
Before the rollback, local boards of election had the discretion to set their own early, in-person voting hours on the three days before the election. People were allowed up until Monday before the Tuesday election to vote in person. Weekend voting varied among the state's 88 counties.
Obama's re-election campaign has previously stepped in to challenge changes to Ohio's election law.
Obama supporters helped circulate petitions last year in an effort to have voters this fall overturn a bill that overhauled election rules. State lawmakers later repealed that measure.
Romney's campaign hasn't weighed in on voting issues in states other than Ohio.
Whether the ability to vote during the final three days matters to Ohio voters remains unclear. People have other ways to vote, including casting an absentee by mail starting 35 days before the election and casting an in-person ballot on other days.
Norman Carmichael, 64, of Columbus, said he's taken advantage of the state's in-person voting rules before and he opposes any move that makes voting harder for people. "I don't think that's fair," he said, when asked about the restrictions on the three days before the election.
Rema Ina, 29, of Columbus, typically votes on Election Day and wasn't aware Ohioans could even cast a ballot in person before then.
"I'm not bothered by it because I didn't even know about it," she said.
Associated Press writer Calvin Woodward in Washington contributed to this report.