The battle for presidential votes in the key state of Ohio is heading to court.
President Obama's campaign has sued the state of Ohio over new rules for early voting designed to benefit members of the military, saying the extra hours should be available to all voters.
That lawsuit prompted claims by Mitt Romney and aides that the Obama campaign is targeting military voters -- a false claim, Obama's team quickly responded.
Said Romney in a statement: "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."
Rob Diamond, director of veterans and military family voting for the Obama campaign, said Romney is fabricating his claim: "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."
Ohio -- with 18 electoral votes -- is not just any member of the Electoral College; it has picked the winner in 12 straight presidential elections.
The Buckeye State figures to be particularly important for Romney; no Republican has won the presidency without taking Ohio.
The lawsuit reflects the intense ground battle between Obama and Romney in up to a dozen battleground states. Both campaigns, plus outside groups, are grappling state by state, country by county, precinct by precinct.
ABC News notes that the flap over Ohio stems from the nationwide battle over voter qualifications:
A series of laws passed in the past year by Ohio's Republican state legislature and Gov. John Kasich have waived the last three days of in-person early voting before Election Day for all but members of the military. Civilians now have until Friday, Nov. 2,to cast those ballots and must arrive at the booth before 6 p.m.
Republicans faulted the extra time for civilians as too costly for local governments and prone to fraud and abuse. Meanwhile, service members were exempt from the restrictions, allowing them to vote at any time before polls close, an extra three days without restrictions.
As previously reported by ABC News, the Obama campaign sued the Buckeye State last month to block those laws from taking effect, restoring weekend voting as it was in 2008. Democrats say those last days before Nov. 6give a crucial extra cushion for Americans who might not have had the opportunity to enter the voting booth in the days prior. If the challenge is successful, they say, military voters would not see any difference in their rights.