I agree that's at least part of it. But I still don't see Schumer bringing along the required number of Senate Democrats to get a veto override.
'Rats adhere to the party line - with rare exceptions like Lieberman himself, who paid a steep price for his opposition to that line on defense issues. Lieberman was in effect drummed out of the Democratic Party.
The problem with being a Democrat first is that the Democrat party has been hijacked by the radical Left and is testing the loyalties of Americans and Jews. How far is Schumer willing to go along Obama's path before even he says "enough, I'm out?"
The problem with being a Republican first is that the Republican party has been hijacked by appeasers who are looking for the easiest way out of any crisis. The radical Left knows this, which is why we have seen a strategy of management by manufactured crisis even since Rahm Emanuel uttered that infamous phrase of never letting a crisis go to waste.
So it's really a confluence of two forces: a party inertia driven by a loyalty to the past that is forcing radical change, and a nonexistent opposition that is afraid of the effort or owning the change.
-PJ