This is the thing with a primary season. If something happens late in the season, then how do you go back and change the results from earlier in the season?
Let’s say for instance Biden listens to all the “sky is falling” pundits and retires now. How does the DNC choose its candidate? I’m not very familiar with procedures for a closed system like that. Do they do an open convention and let the delegates vote on whoever they want? Do they have a list of candidates to vote one at the convention? Who makes up that list?