What could the polls be missing?

Hypothesis #1: The polls are underestimating Clinton because they don’t factor in her superior ground game.

Most reports (and we’ll have an article with some extensive data on this soon) suggest that Clinton is far better organized than Trump, with more field offices, for example, and a better get-out-the-vote (GOTV) operation. Isn’t that reason to think the polls are underestimating Clinton by a bit?

natesilver: That’s one of the better arguments, yeah.

harry (Harry Enten, senior political writer): Well, the question you have to ask yourself is whether or not the field game is being picked up by the polls. In a wonderful, perfect universe, it would be. In reality, I have my doubts. That’s why I’m not entirely sold on polls showing a large gap (in Trump’s favor) between registered voter results and likely voter results.

natesilver: The empirical literature on the ground game is messy because there are so many conflating variables. But what would worry me if I were Trump is that the race isn’t that close if everyone turns out — and I have the worse turnout operation.