Very cool visualization of the differential between the AG/senate and presidential races, by county!

One viable explanation for the dropoff you highlighted is an incumbent and/or popular Democratic senate candidate who successfully captures Republican voters across counties. That is, a Democratic senate candidate who is beloved by many Republicans who otherwise vote along party lines (i.e. for President). How do you rule that explanation out?

How does the 2024 data compare to prior elections in these states or with popular Democratic senate candidates and a tight presidential election?

How does the data look in all 50 states?