Honestly think the 2016 hack/dump of how the DNC fucked over Bernie has split the left in a terrible way. Russia knew what it was doing. Now his name's not even being floated or polled. It could repair/unite ppl this current dysfunction does seems squarely inside party apparatus not wider left.
Bernie's even older than Biden. Given that the move to oust Biden is attributed in large part to his age, nobody can bring up Bernie as an alternative without undermining their own point.
Bernie is an independent except for his brief membership to run for the White House. It's unrealistic to expect the party to be nice or loyal to him all the time. It's awesome that he caucuses with them, but he is still an independent. I say this as someone who loves Bernie and his policies.
The left was saying Biden's age was gonna be a problem all along!