Why I am optimistic about Kerry's chances: a profile of pollster John Zogby in the New Yorker contains the following story,

"How do I get a handle on this election or any other?" [Zogby] asked..."I asked one question the Saturday before the election in 2000. I called my call center in Utica and said, 'Put this in the poll: "You live in the land of Oz,and the candidates are the Tin Man, who's all brains and no heart, and the Scarecrow, who's all heart and no brains. Who would you vote for?"' The next day, I called Utica and said, 'Whaddaya got?' They said, 'Wel we've got Gore--,' I said, 'I don't care about Gore. What's Oz?' It was 46.2 for the Tin Man and 46.2 for the Scarecrow. It was right there that I knew I wasn't going to know what was going to happen. But I asked this question again two weeks ago and the Tin Man led by ten points."