Biden isn't going anywhere. As he remains solidly the frontrunner this is still his nomination to lose. As for the race issue, I find it incredible that quite a few supporters of 45 doesn't understand or want to acknowledge his complicity. The coded language he used during the campaign and just outright nationalistic language he uses now is what's pouring gasoline on the fire.
He is the most raw occupant of the oval in modern history. Meaning he doesn't have a filter, he has no skills as a statesman, thus he says the wrong thing at the wrong time, he appears to be totally incapable of empathy, and when he makes outright racially charged remarks he turns around and says I'm the least racist person alive which totally lacks credibility.
Now Biden in his long career is known as a gaffe machine. He even calls himself that. But it's not so much the flubs he makes but rather his words and actions that can be measured over the decades. In that regard no one can credibly call Biden a racist in any way, shape, form, or faction. So when he misspeaks about the issue most people just look, shake their head, and think he means well, we know what he was trying to say.
I have told my kids since they were young that having a good reputation will buy you a few mulligans when you inevitably screw up. That's why Joe gets a pass and 45 does not.