We must vote for Biden in November if he's still on the ticket. MUST. Fascism is NOT an acceptable alternative.
HOWEVER
The recent high-profile defections of Dem Congresscritters from the presumptive nominee and incumbent president, however, is a political crisis great enough that it probably warrants replacing Biden on the ticket, even if the ONLY issue was the loss of confidence of his party. That is a major fucking blow that you can't really get back.
So, we must vote for the Dem ticket in November, including if it is not Biden, which is currently a possibility, barring some insane situation like them offering Hitler's brain in a jar.