Expected. Winning a Democratic primary is about putting different ideological/ethnic coalitions together, and the primary calendar/delegate allocation rules make winning Black Southerners vastly overpowered. Whitmer is a candidate for Chicago wine moms, but when did they ever decide a Democrat primary?
Raphael Warnock or Wes Moore, 2028!
Black southerns support the "establishment". If Harris doesn't run in 2024, I could see black voters 40+ supporting Whitmer. But that depends on Warnock not running
What makes Whitmer part of the "establishment"? She's the progressive governor of a Midwestern state; if anything, she is more Sanders/Warren than Biden/Harris.
Black Southerners are mostly low-information voters who strongly weigh visible idpol factors. Biden didn't win South Carolina because he's "the establishment", he won because of nearly 100% name recognition and the warm, fuzzy vibes that came with being Obama's VP. Polls showed that, in a sans-Biden race, most Black voters would have
supported Sanders.