Not sure if there's anything to be gleaned from the raw changes, but there may be something in the intra-state variation. Population changes, primary calendar changes, and changes in competition levels play a role here (at least the 2020 PPE was almost uniformly non-competitive), too, but there seems to be more going on than that. Trump seems to be holding up better in Hispanic areas and doing okay in the Black Belt. He also seems to be doing relatively well in exurbs and poorly in educated suburbs/smaller metros while urban cores seem to be a mixed bag.
Thoughts?