Whats round on the sides, hi in the middle, and probably the biggest battleground of all in 2012? Ohio. Obama carried the state in 2008, and holds a narrow 2 percent lead going into election day, according to polling averages. A factoid surely not lost on Gov. Romney: No Republican has ever won the White House without winning Ohio, making the states 18 electoral votes all the more precious. Polls close at 7:30 p.m. Eastern.