Is Cuomo even endorsing these guys?
He hasn't endorsed yet. Also worth noting that the "Working Families" Party has backed away from Liu/Koppell too.
As far as I'm concerned, de Blasio is a Republican now too. He can be Bernie f***ing Sanders for the rest of his term - if you support Jeff Klein or Tony Avella, you have no place in the Democratic Party.
I wouldn't worry too much about DeBlasio no longer being the great hope of liberals over this. He's clearly supporting them as part of a deal to make the state senate Democratic and help redistricting. Later he can tell them to pound salt when there's a solid majority in the senate.
Are Klein or Avella in any serious danger of a primary anyway?