Washington: With an extremely close White House race looming, the campaigns of both President Barack Obama and Republican challenger Mitt Romney are reported to be preparing for possible long battles over Tuesday's vote.
Even before Tuesday's voting began, the two sides were already skirmishing over the validity of provisional ballots in the battleground state of Ohio increasing the possibility of a delay in the final result, according to the Washington Post.
Election officials there are facing a lawsuit over how provisional ballots -- issued to people whose eligibility to vote at a particular precinct was in question, or if they requested an absentee ballot but didn't return one -- should be filled out, CNN reported.
A federal judge has set a hearing for Wednesday on the issue. But Ohio's secretary of state Jon Husted, a Republican, said on Sunday that the process "is consistent with the courts and consistent with the law."
Husted had already been taken to court for trying to cut off early voting in the three days before Tuesday, with Democrats accusing him of trying to suppress the votes of Democratic-leaning constituencies. Husted called that "an absurd notion."
In Florida, another vote-rich state where polls show Obama and Romney running neck-and-neck, there were still long lines for early voting when the deadline passed over the weekend, CNN reported.
So election officials in the state's most populous belt -- Palm Beach, Broward and Miami-Dade counties -- allowed voters to pick up, fill out and submit absentee ballots.
In Miami, the lines snaked around the block from the office of the county supervisor of elections ahead of a Monday afternoon deadline, the news channel said.
Florida Republicans, led by Governor Rick Scott, had pushed to cut the number of days available for early voting from 14 to eight.
Democrats went to court to get that period extended, arguing the polling facilities in south Florida, a Democratic stronghold, weren't up to the demand.