Are there any liberal activists threatening Kucinich and Grijalva with a primary challenge over this, or do they get a pass because they're against it for "noble reasons"?
They almost certainly get a pass.
The liberal base would agree anyway - it's a shame that Obama didn't even put single-payer out there as a possibility for the Republicans to rip into. We know they are going to call it socialism and obstruct passage regardless of what the bill actually contains, so why begin by compromising half of your side in the first place?
I was thinking about this the other day. If they had started out with single-payer, knowing it wouldn't pass, and then went for a public option as a compromise, they may have had more success with moderate Dems and Republicans.
