Gallup polls taken since 1952 suggest that the candidate leading with around week to go is usually victorious, albeit by a smaller margin in actual votes.

Gallup polls of American voters have shown a significant change in attitude in the last twenty years, from 73% opposed to home education in 1985 to 54% opposed in 2001.

Obama's popularity dropped by 5% in the polls during the past week, with most putting him around 45%; but a Gallup poll at the end of last week had support for him at just 40%.