I think Biden doesn't last.
1. Democrats trust congressional leaders in a way that Republicans did/do not trust theirs.
2. Democrats trust NYT/WaPo/Network TV in a way that Republicans did/do not. (Caveat, opinion on MSNBC is actually not united)
3. Management of the aftermath has been bad, including with outreach to congressional members.
4. Biden trusts Obama/Pelosi/Klain in a way that Trump never did w/ Priebus et al.
5. The rules are clear that he CAN be pushed out at the DNC.