That's fine. It just seems that a lot of replacement calls are conspicuously absent of that condition.
Because we're in uncharted waters, so there is no playbook for replacement. Biden has also decided to fight it strenuously, which is why it's still at best a 50/50 that he steps aside.
Right after the debate, Newsom's name was bandied around quite a bit. But beginning in early July, it's been seen as either Joe Biden or Kamala Harris at the top of the ticket. Whatever happens next, Harris has solid party support because she's astutely remained loyal to the Biden campaign. Like many others here, I'm nervous about her chances across the battlegrounds. But can people honestly say that Candidate Biden will do better (than he's been doing) over the next 3.5 months? Obviously there's risk either way.
Finally, if there was to be a "contested primary campaign" right before the DNC as some pundits suggested, we've just wasted 2.5 weeks of time, and counting. So the chances of several top candidates barnstorming and trying to build support before a contested convention seems far-fetched at this point.