I still think Harris fits the Tier 1 description. There’s no real reason to think she can’t win. She raised a decent amount of money, her favorability ratings are roughly as good as anyone’s, party activists like her, and she’s the only woman or person of color in a top tier full of white dudes.
But I wonder why Harris hasn’t gotten more endorsements. Harris fits the archetype of a coalition-building candidate, and endorsements are a pretty good benchmark for how well you’re building your coalition. Instead, Biden pulled ahead in our endorsement tracker after just one day and is already getting endorsements from black leaders that Harris is missing.