I'm inclined to think the polls have completely broken down.
We simply don't have the experience or background data to be able to assess what's going to happen in this election robustly.
This is all pretty new stuff, it'll take a while for there to be enough data to produce sound predictions.
EDIT:
http://fivethirtyeight.com/interacti...n-predictions/
Just look at how wide the 90% confidence range is.