At this point, like most people, I think it's gonna be Harris. She has great rapport with Biden, she covers all his gaps, and it's becoming more clear that she's who he personally wants.
Except for the ideological gap. A Harris pick does nothing to bring Bernie/Warren supporters or those in their coalition on board. This was a mistake Hillary made with Kaine in not trying to shore up unity in the Party.
Eh, I don’t think she’s as bad for that as a lot of fellow lefties make her out to be. Not that I’m necessarily her biggest fan, but Harris comes across as a lot more committed to activism, specifically youth activism like March for Our Lives or BLM, than somebody as say Klobuchar (who is the only one on his shortlist that I think would actively hurt Biden’s odds). Millennials, who make up for the bulk of the ideological divide, still love Obama. Dems can win with his politics, they just don’t seem to quite understand the sense of urgency among young people, see the popularity of a revolution.
So, all that’s to say you can’t win over Bernie diehards with a VEEP, maybe Bernie himself but obviously that’s not an option. I think the key is more so exciting his softer supporters, and there are a lot more than are acknowledged, by hearing their urgency, and Kamala can pull that off.