Who is this "Democrats" that you are trying to steer, by shitting on Biden? Democratic voters?
You have one. I am steerable. I am going to vote in the Democratic primary soon. Presumably, the person who wins in the primaries will have the nomination. Who should I vote for instead?
Because relentlessly trashing Biden as a way to get a replacement, without bothering to even figure out who that replacement might be, during the middle of the process which literally requires and only requires that voters agree on a replacement, seems a little not-quite-matching-the-priority-you-are-claiming-is-the-priority.
(I know, Bernie Nevada it's not that simple et cetera I know. The point that I'm making is that Bernie was an identified person who people could vote for. No one was relentlessly making memes about how Hilary was bad without bothering to support anyone else in particular, and then claiming they were just looking out for the Democrats because they were just concerned she wouldn't be able to beat Trump, and explaining all the ways she sucked and waiting for someone else to figure out who instead.)