X axis: state life expectancy at birth in the election year (or nearest year available; 2024 uses 2022 numbers). Y axis: Democratic vote share minus Republican vote share. Colors mark Census-Bureau regions. Sources: presidential vote from MIT/MEDSL (1976-2016) and Wikipedia (1960-72, 2020, 2024); life expectancy from the U.S. Mortality Database (USMDB).
There's nothing remarkable about it. All one has to do is hit the right keys at the right time and the instrument plays itself.