A few weeks after the midterms, something happened that largely flew under the radar. Democrats were celebrating a successful election, and giving all the credit to President Biden. And against that backdrop, the party made an announcement: It would be changing the order in which states voted in the primary election, moving South Carolina first. The party was talking about it in terms of representation and acknowledging the role of Black voters.

But given that South Carolina essentially saved Mr. Biden’s 2020 candidacy, Astead wondered: Was something else going on? We headed to the party’s winter meeting as it prepared to make the change official.