Creepy Uncle Joe is the ultimate insider of the Democratic Party establishment, so when he endorses someone you know that he's not doing you any favors.
So who has Biden endorsed? Darren Soto is one.
Soto is notable for only one thing - who he's running against.

Cynthia Nixon is still a long ways back in the polls, but she's moving up.

If the polls are to be believed, Cynthia Nixon is going to be absolutely crushed by Andrew Cuomo in the Democratic primary.
So why should I care about Nixon's futile campaign?