R votes were about what they were in the past. What we really need to know is whether these are almost entirely people who have chosen R in the past. If yes, then the big question for Rs is “why would they accept him?” If it’s lots of new R votes, compensating for lots of Rs who didn’t vote for R again, then the question is “why these new Rs for this election?”
D votes are down relative to the past. What we really need to know is whether this is primarily because lots who voted D in the past either
stayed homedidn’t vote (whether by choice or because of suppression) or voted third party. If yes, then the big question is “why didn’t they vote for D again?”
If neither of the above accounts for what happened, then the implication is that a non-negligible share of people who had voted D in the past were actually comparing what R and D had to offer, and at least in a select set of districts in a select set of states, chose R. Then the big question is “why would they switch?”
My current belief, based on results (vote shares, vote share swings, and vote totals) and my own understanding about voters, is that 3 is unimportant, asking about the relative appeal of the R vs D candidates is irrelevant, and better understanding would come from examining why Rs do what they do as Rs and Ds as Ds. But my belief about this would change if I saw individual-level survey data or voter file data suggesting that 3 is in fact important.