It's honestly tragic that wanting to ban high-capacity magazines is more of a litmus test than actually betraying the party.
This is why I left the Democratic Party - they don't even have the balls to punish the people that betray their own.
Cuomo's victory had nothing to do with wanting to ban high-capacity magazines and everything to do with having solid backing from pretty much all key elements of the New York City Democratic machine while also being a very popular in both Long Island and (albeit to a somewhat lesser degree, IIRC) the NYC suburbs.