Biden supporters on social media are excoriating Democrats who are openly calling for him to step aside, especially people like Adam Schiff who did it publicly. They're saying Biden deserves the nomination because of his record, his deep care for the country, and his primary wins. But if it's true that others — Raskin, Pelosi, and especially Obama — are offering the same counsel, if mostly behind the scenes, that's significant.
If Biden bows out, which I'm not yet fully convinced he will or should do, what he says to the nation will matter. He will have to convince Americans that he is not being forced out, but is making the decision on his own after extensive consultation, and that the best way forward to defeat Trump and authoritarianism is for another candidate to be at the top of the Democratic ticket. This would indeed be the most consequential speech of his career.
The question will be who should replace him, but regardless of who that is, Biden and the party will have to rally around them and their running mate quickly. There are huge practical hurdles, including how to use funds already acquired, redoing millions of campaign materials, staging and re-staging events, and so on. Some say this is impossible, but it could be an energizing shot in the arm that starkly contrasts with Trump's cult.