Reasons not to take the Gallup poll seriously
1. Gallup's model for detecting likely voters is never right this far out. Was their final poll in 2000 close to the actual result? Yes. Was it close in late September? No, they showed Bush ahead of Gore by 8, 50-42. It actually ballooned to 13 points in mid-October, 52-39. In the real world, Gore won by half a point, making Gallup's mid-October poll off by 13.5 points. Did Gore make one of the great all-time comebacks, convincing some 7 million voters in the last 2 weeks? Of course not. Gallup's poll sample just sucked. It still does. They weight for census information, and go out of their way to get men on the phone, but refuse to weight for party ID. I know there are reasons not to, but the result is Gallup polls fluctuate wildly. It's not because so many people change their mind so quickly. It's because they're holding firm to an, apparently, outdated likely voter model. More numbers/info on that score here.
2. As we learned 4 years ago, the national polls don't matter. Even if the non-Gallup polls, showing Bush up by 3 or 4 are accurate, and they probably are, he could easily win by that much and still lose the Presidency. I've said it a million times, but if Kerry wins Florida, Kerry's going to win. Even the wrong-headed Gallup poll has Kerry down only 3 in Florida, way inside the MOE. The state polls, spread over all the polling firms out there, just simply do not support the Bush landslide predictions that the Gallup poll is suggesting.
3. If the voter registration numbers are correct in stories popping up, there could be an unprecedented number of first-time voters. Personally I believe change is a more compelling motivator for that kind of thing, than is status quo. It's reasonable to believe they signed up to help kick out the shrub. This could make the likely voter model that much farther off.
4. Their founder believes "the most profound purpose of polls is to see how people are responding to God." Wonder which candidate the Gallups are rooting for?
5. Undecided voters tend to break for the challenger 2 to 1, at least that's what everyone is saying. If this race is in truth closer than Gallup says, and if the undecideds go against Bush at that pace, then as far as I'm concerned it's basically tied. And then it's all about the state numbers. And if Kerry can get through this week's debate without totally falling apart in the presence of debate master Bush, he might even gain a point or 2 in the next Gallup poll.