Four years ago Ohio delivered the presidency to George W Bush over John Kerry, and in 2008 the Buckeye State may again prove decisive. Both camps have legal teams to contest the results of the Ohio vote, which could be compromised by a host of snags: faulty electronic machines, irregularities on the rolls, and above all provisional ballots, which Ohio has used more than almost any other state in recent elections.
As the New York Times reports, Ohio uses provisional ballots in cases ranging from a late arrival to a misspelled name. They aren't counted until after Tuesday night, and disqualifying them is child's play for an election lawyer. This year, high voter registration will probably mean more provisional ballots than ever—and, said one Ohio election law expert, "The larger the number of provisional ballots cast in a state, the more vulnerable the Achilles’ heel."