Nate Silver @NateSilver538
This is why it'll be hard for further polling to move our numbers all that much in the Big 6 states (PA/WI/MI/FL/NC/AZ). One new fairly decent poll of PA will still get only 5% of the total weight there, or thereabouts. A very good poll with a large-ish sample might get 10%. — PolitiTweet.org