Possibly even more significant is it's estimated another 25 percent could still change their minds.
In Tuesday's Presidential debate both candidates will work to win over these undecided voters, and to keep the support they've already gained.
THV spoke to voters who say they'll listen closely to what McCain and Obama have to say, but many are already leaning in one direction. Students in a American National Government class at ULAR are reflective of voters all over the country. Most like Kristin Hester and Cody Ussery are firmly backing a presidential candidate.
"I am strongly favoring McCain, because of the fact that he has a lot of my same views," says Hester.
"I definitely decided to vote for Obama," says Ussery.
While others like Adam Eascham say they're leaning one way, but could sway.
"I'm actually leaning towards Obama right now, because of his position on gay rights," says Eascham.
A recent poll by the Associated Press and Yahoo news found that 18 percent of voters are undecided, of these folks the economy was rank as their number one issue.
American Politics professor Joseph Giammo says undecided voters usually fall into two groups. The smaller being the well informed yet indecisive. The larger being people who are late getting involved.
"So for that group certainly what the campaigns do over the next few weeks could make a big difference," says Giammo.
Tuesday night political strategists say Obama and McCain will focus on undecided voters. Professor Giammo points out since polls put Obama slightly in the lead with voters, McCain would benefit from a discussion highlighting his strengths, such as experience.