… First, some good news for the polls: Assuming current results hold, the only states where presidential polling averages got the winners wrong will be Florida, North Carolina and the 2nd Congressional District in Maine. …
The better way to evaluate polls is how close they come on vote margins, and this year, polling margins will be fairly far off in several swing states as well as in national polls. As of this writing, Biden leads by 3.4 percentage points in the national popular vote. We expect him to improve on that some, as there are still a number of votes to be counted in blue states such as New York, California and Illinois, so he’ll probably finish with a lead closer to 4 points or possibly even a bit larger; 5 points wouldn’t shock me. In any event, we should expect a miss of around 4 points from Biden’s final margin of 8.4 points in national polls, though as I said at the outset, this is actually pretty normal by historical standards. CONT.
Nate Silver, FiveThirtyEight