Fifteen Ohio military groups have gone to court to oppose an “offensive” lawsuit filed by President Obama’s campaign that challenges a law allowing military members to vote on days when the rest of the state cannot.

“The Obama campaign’s and Democratic National Committee’s argument that it is arbitrary and unconstitutional to afford special consideration, flexibility, and accommodations to military voters to make it easier for them to vote in person is not only offensive, but flatly wrong as a matter of law,” the military groups — which include the Marine Corps League, the Association of the U.S. Army, and the Association of the U.S. Navy — argued in their filing.

Republican presidential candidate Mitt Romney also attacked Obama over the issue. “President Obama’s lawsuit claiming it is unconstitutional for Ohio to allow servicemen and women extended early voting privileges during the state’s early voting period is an outrage,” Romney said in a statement today.

Ohio’s current early voting law allows only members of the military to go to the polls during the three days before the elections. The early voting period for the rest of the citizenry ends on the Friday before the election.

The Obama campaign told an Ohio federal judge that the law produces “arbitrary and inequitable treatment of similarly situated Ohio voters with respect to in-person early voting.” The campaign asked the court to block the law, “thereby
restoring in-person early voting on the three days immediately preceding Election Day for all eligible Ohio voters,” according to the filing.

“This lawsuit, at bottom, seeks to treat all Ohio citizens equally under the law,” Donald McTigue, general counsel for the Obama campaign in Ohio, told Bloomberg News in July.

The Obama campaign is not requesting that the court limit the opportunities of military members to vote, but that might be the effect of their lawsuit if it succeeds. Secretary of State Jon Husted said that the old law did not create consistent early voting rights across the state, because most local jurisdictions decided to close for the weekend.

“I didn’t see a lawsuit occur when six counties had weekend voting and extended hours and 82 of them didn’t,” Husted told The Associated Press. “I’m sympathetic to the idea that we should have consistency, because that’s exactly what we’ve been doing on a number of fronts.”

The Obama campaign estimates that 93,000 people took advantage of the weekend early voting in 2008.