The polling is all bullshit because the caucus system does not weight all precincts equally. Many rural precincts have a disproportionate influence in relation to their population in the state. This means that the pollsters are all under-counting rural votes and Edwards has many of these rural counties locked up. But Fineman makes the point that Edwards will get screwed because even if he wins Iowa late in the day, the exit polls will initially show he lost because like all the polls they will have underrepresented the rural vote.
http://www.msnbc.msn.com/id/22217110/Quite simply, this Iowa debate (and Iowa itself) is his first and last chance. He has placed all his money and bets for years on Iowa, where he is practically a local at this point. He absolutely HAS to win to get the media attention he needs to leverage his effort here into national momentum. He has the best, most cogent and inspiring stump speech, and a good, loyal organization. He could get pummeled by media dynamics. There will be exit polls on caucus night, but they will not be an accurate reflection of the final tallies of caucus delegates – the legally meaningful number – until later. Also, he is strongest in the small western towns, whose disproportionate influence in the delegate tallies (don’t ask) won’t show up in the exits. In other words, he could win but not get credit for it by the time the winners are declared.