This blog post is based on the previous one The Arithmetic of Presidential Elections. There we used data from the last three presidential elections to argue that there are Red States with 170 electoral vote, Blue States with 215, and Swing States listed below with 153.

Turning to https://projects.fivethirtyeight.com/polls/president-general/2024/

for data, we see that Biden trails in every swing state

States               Votes                 Biden                 Trump

Ohio                   18                        36.8                    46.1

Georgia             16                        38.3                    44.8

Arizona              11                        38.9                    43.9

Iowa                   6                          32                        50.4

Carolina           15                       38.0                    45.2

Florida               29                        36.5                    46.1

*Penn.               20                       41.6                    43.6

*Wisc.                10                        41.8                    42.8

Nevada              6                          38.7                    42.6

*Michigan        16                        41.2                    43.0

*New Hamp.   4                          42                        44

Since this predicts Biden will only carry the Blue States this gives the prediction above.

Flipping the four closest states marked with * would result in 273 – 265 but likely the polls do not yet fully reflect his abysmal debate performance.