Biden keels over at the end of September. The DNC tries but fails to propup Kamala as the nominee. They drag their heels till mid October and begrudgingly give it to Bernie.
But they waited to long so now Bernie has no time to campaign and loses to Trump.
Dems use it as an excuse to purge anyone to the left of Biden.
Theory: Biden is already dead and the DNC is Weekend at Bernies’ing him through the election replacing him with CGI Biden and pre-recorded speeches.