Some 6.4 percent of voters remain undecided in the closing days until the election.
Who are these people who still can't make up their minds — after dozens of debates, two conventions and perhaps a billion dollars' worth of advertising?
According to Andrew Kohut of the Pew Research Center, 63 percent of undecided voters are female. Twenty-seven percent are age 65 and older; many tend to be less well-educated and more religious than voters who have already picked their candidate.
Kohut says that the number of voters still undecided is typical at this stage of a presidential campaign: "You're never going to get everyone giving you an answer, and the numbers that we're seeing in '08 are the same as '04 and '00."
When voters are asked by pollsters why they remain undecided, their answers typically put them into three categories, Kohut says: the conflicted voters who feel torn between Republican John McCain and Democrat Barack Obama; the disengaged voters who have not been paying attention to the campaign; and the nonvoters.
"There's some real reason for these people to not being able to make up their mind," Kohut says, "in addition to the fact there's a component of them who are disengaged, who probably won't vote."
Among the undecided voters interviewed, some say they worry about Obama's qualifications or his ability to fix the economy, Kohut says; some say they have doubts about McCain's health care policy.
In the end, Kohut says, Pew's analysis shows that undecided voters are going to divide up fairly evenly — although they may be slightly more supportive of McCain than voters who have already made up their minds.