Twenty-two percent of swing-state voters are either undecided (5%) or say there is at least a slight chance (17%) they may change their vote preference between now and the election, underscoring the competitiveness of the election and the uncertainty about its ultimate outcome.

That 22% of swing-state voters includes 10% who currently support Obama and 7% who now prefer Romney. The candidates have roughly the same percentage of committed voters — 39% of Romney supporters and 38% of Obama supporters in the swing states say there is no chance they will change their mind.