I don't think the polls are inaccurate per se. I think that, in many ways, they reflect the reality how people get their news, and the resources availble to the two candidates.
Bush has given fewer news conferences than have been recorded for any President. Certainly since the Civil War. His handlers very carefuly control his images. When he gives interviews, it's Republican-controlled interviewers Answering carefully scripted questions. When he finally agreed to appear before the 9/11 commission, it was only with Cheney at his side, and only questions of a very limited scope. To get into a campaign event, you have to have a ticket, and usually sign a loyalty oath. And the only way to get a ticket, for 90% of people, is to work on a Republican phone bank. He simply doesn't take independent questioning.
The one time people have SEEN Bush react under pressure before this past debate is captured for all to see in Fahrenheit 9/11. When informed of the 2nd plane hitting the World Trade Center, he completely froze. He was totally unable to give commands in a crisis.
The other side of the coin is, Bush has alomst 200 million dollars to spend onhis advertising campaign, and a lot of it has been spent denigrationg Kerry, and funding/supporting things like the SwiftVets smear campaign.
The result of all this? Bush supporters, AND 'undecideds', thought Bush is a vastly smarter, more competent leader than he is. Bush supporters, AND 'undecideds', thought Kerry vastly LESS competent, less principle, and less consistent than HE is.
And then the debate came. And Kerry turned out to be calmer, better informed, and more cogent than Bush relentless campaign advertising had led people to believe. And Bush was exposed as, well, unfocused, and unthinking, capable of repeating what he's trained to say, but almost without the ability to think on his feet, or accept challenge calmly.
People saw that there's less to Bush than he carefully crafted image, and that there's more to Kerry than they'd been led to believe.
But it's all about what people have an actual chance to see. The polls have refected people's intentions based on what they've seen of both candidates. The debate was the first time they got to see them measured directly against each other.
There's a website I very much like caled http://pollingreport.com
They give you the results of all the most recent polls. Kerry got as big a bounce off the debate as Bush did off the Republican convention.