The Obama campaign filed a lawsuit last month or something to claim that it was unconstitutional for Ohio to allow military voters early voting time in the three days before the election without extending the same time to all Ohio voters. Mitt Romney predictably lied about it saying Obama was trying to take away military voting rights.
Now, this is a very complicated issue here, and not everyone will be able to follow this: until last year, all Ohio voters could vote early. Then the GOP passed a bill taking away early voting for everyone but members of the military. Now the Democrats are suing to get early voting reinstated for everyone. Now that was REALLY complex, but I hope you able to follow it!