In a move that puts new meaning to the term battleground, President Obama's re-election campaign and members of some military groups are on a collision course over voting rights in the critical state of Ohio.

The Obama campaign and the Democratic National Committee have filed a lawsuit to block a new state law allowing men and women in uniform to vote up until the Monday right before an election, while the cutoff on early voting for the rest of the public is three days earlier.

Top Obama campaign officials told Fox News in interviews that the lawsuit in no way tries to restrict the voting rights of military members. All they are trying to do is even the playing field for all voters in Ohio by allowing early voting up until Monday for everyone, including members of the military, because they believe a two-tiered, early-voting process is unfair.

"Along with the DNC and Ohio Democratic Party, this campaign filed a lawsuit to reinstate equal, early-voting rights for all Ohioans -- rights the Republican-controlled legislature arbitrarily stripped away this past year," Jim Messina, Obama's campaign manager, told supporters in an email.

However, the National Guard Association and other military groups have fired back, saying it's "offensive" for Democrats to suggest in the lawsuit it's arbitrary for service members to get special consideration.

Men and women in uniform typically get more time than other voters to send in absentee ballots since they may be serving in an overseas or domestic location that is not close to their home polling station.

"I'm just outraged by this," Mike DeWine, the Republican state attorney general in Ohio, told Fox News. "I can't believe the Obama campaign and the state Democratic Party are actually saying there's no rational basis for a distinction between someone who is in the military voting and someone who is not in the military."

The stakes in this legal battle are huge because Obama is anxious to keep Ohio's 18 electoral votes in the Democratic column this November. He has already visited the state nine times this year alone.

Since no Republican has won the White House without carrying the Buckeye State, GOP Presidential candidate Mitt Romney is fighting just as hard and on Friday lashed out at the Democrats’ lawsuit.

“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," he said Saturday. "I stand with the 15 military groups that are defending the rights of military voters, and if I'm entrusted to be the commander-in-chief, I'll work to protect the voting rights of our military, not undermine them.”

The Obama campaign responded Saturday by saying, "Mitt Romney and his campaign have completely fabricated a claim that the Obama campaign is trying to restrict military voting in Ohio. In fact, the opposite is true. The Obama campaign filed a lawsuit to make sure every Ohioan, including military members and their families, has early voting rights over the last weekend prior to the election."

While the lawsuit does not restrict the ability of military personnel to cast their ballots early, both sides know how volatile an issue this can be.

When Democrats tried to block some military ballots in Florida during the contentious recount of 2000, it was a political and public relations disaster -- until then-Vice Presidential nominee Joe Lieberman intervened.

"Vice President Gore and I would never authorize and (would) not tolerate a strategy that was aimed at disqualifying military ballots," Lieberman told "Fox News Sunday" shortly before Gore conceded the election to Republican George W. Bush.

Military veterans in Ohio who support Obama stress that this time nobody is trying to prevent service members' votes from being counted.

"I just find it troubling that the Republicans would use veterans groups as cover fire for their real mission," former Congressman John Boccieri, D-Ohio, told Fox News in an interview. "Their real mission quite obviously is to restrict people from voting three days before the election."