If you take the polls at face value right now—with Biden gaining/holding steady in AZ, WI, MI but losing ground in PA & FL, then Arizona is the tipping-point state right now, which could lead to the map shown here. This is a winning map for Biden, but it's precarious. pic.twitter.com/bLTzvk2E3l

— Nate Silver (@NateSilver538) September 8, 2020

Chance of a Biden Electoral college win if he wins the popular vote by X points:

0-1 points: just 6%!
1-2 points: 22%
2-3 points: 46%
3-4 points: 74%
4-5 points: 89%
5-6 points: 98%
6-7 points: 99%

— Nate Silver (@NateSilver538) September 2, 2020

He's right, that Biden would win if the election were today. But we live in the most politically dynamic environment ever. Not only does information flow at an enormous rate, but circumstances can change overnight with a single effective coronavirus treatment or news of a date certain of a vaccine release.

- Ref