As i said many times - JBE and, probably, Beshear on Democratic side, and Baker, Hogan and Phil Scott - on Republican, are examples of "the last of Mohicans". After them - US elections will become even more predictable and boring... They already are in 98% of cases, they will - in 99.9%. Only fundamental change in party system can help to avoid such situation...
I don't think the moderate Rs on the East Coast will die out, given how Scott/Baker/Hogan have all won landslide victories during D waves and presidential years. Red states do seem to be getting redder on the state level though.