Most voters already know which candidate they want to see in the White House for the next four years, but some still have no idea who they want to vote for.
In these next two weeks, both candidates are going to try very hard to get those undecided voters to make up their minds.
We asked Lynn Vavreck to weigh in on this. She's a professor of political science and communications at UCLA and has been traveling around with us for a few of our election road shows. Lynn researches voters, especially the undecided ones.
Vavreck says that while there aren't very many undecided voters, most of those who are undecided are women. And the reason they haven't decided? They're just not paying attention to the race, perhaps because their lives are too busy.
"They tend to have more children in their home than women who are decided," says Vavreck.
But this won't stop both presidential candidates from campaigning heavily for those potential votes as we get closer to Election Day. Vavreck says we'll most likely begin to see more attack ads, especially in the last week of the campaign, because those are generally more effective with undecided voters.