Why is Biden +9.1 in our national poll average but +7.8 in our forecast?

* The forecast still assumes just a teensy bit of tightening (about 0.4 points toward Trump)
* The forecast is mostly based on state polls, which have been more consistent with an ~8 point lead than 9-10.

— Nate Silver (@NateSilver538) October 26, 2020