Compared with many previous elections at this point in the campaign, more voters this year say they are absolutely certain to vote for their chosen candidate. Only 22% of registered voters (and 18% of likely voters) can be classified as swing voters (undecided, only leaning toward a candidate, or say there is a chance they might change their mind).

Four years ago, 27% of voters were still open to persuasion at this point in the campaign. Between 1992 and 2000, about three-in-ten voters in September were not yet certain about their choice.

In a survey conducted Sept. 12-16, 43% of all registered voters say they are certain to vote for Barack Obama, while 35% say they are certain to vote for Mitt Romney. Among less certain Obama voters, 3% only lean to him and 5% say they might change their mind. Among less certain Romney voters, 3% only lean to the Republican, while 3% say there is a chance they might vote for Obama. Just 7% of voters decline to indicate any preference between the candidates. Read More