Besides the presidential race, two other big races are drawing Hoosiers to the polls Tuesday.
Voters are deciding who will fill Sen. Richard Lugar's seat.
Republican state treasurer Richard Mourdock is in a close race with Democratic Representative Joe Donnelly. Donnelly pulled ahead in polls last week after Mourdock made controversial remarks about pregnancy resulting from rape.
Mourdock told reporters he was "very, very optimistic." After over 600 days of campaigning, Mourdock said he was "a little bit weary" but said he was being helped along by caffeine and adrenaline. Mourdock said he was expecting a huge Republican turnout.
Rival Joe Donnelly said he planned to campaign until the end of the day - as if he had ten days to go and he was ten points down.
"We're just going to spots all over central Indiana to thank voters for taking the time to vote and for being part of this," Donnelly said. "I'm optimistic but we're gonna work non-stop right through."
Libertarian Andrew Horning could draw enough votes to sway the outcome of the hotly contested race. A Howey/DePauw Indiana Battleground poll found Horning with about six percent support. The same poll put Donnelly ahead of Mourdock 47-36 percent.
This election will also decide who will lead Indiana into the future.
Former Indiana House Speaker John Gregg hopes to win the top spot for the Democrats. Republican Congressman Mike Pence, who has had strong numbers in several polls, hopes to keep his party in the governor's office. Rupert Boneham of "Survivor" television fame is the Libertarian.
"We're very encouraged at the support we've received around the state and we're very hopeful about this evening. But today really belongs to the people of Indiana. We'll always count it a privilege to have the opportunity to run for governor of Indiana and we'll wait and see what the Hoosier voters have for us tonight," said Pence.
"Our campaign has really been about trying to cast a positive vision about how we take our state from good to great. We've worked to build an organization all over the state. We hope that's been effective in carrying our message," he added.
John Gregg said he was feeling "real good" about his chances.
"Today's been the same as it always has been. People look beyond the party labels and we've been targeting Independents and liberal Republicans and we've closed the gap and we're gonna pull off a victory," Gregg Said.