This was a revealing final paragraph of Congress Daily's article about Tom Carper's plan to replace the public option with what amounts to state-level triggered co-ops (emphasis added):
The Democratic aide said staffers have tried to keep Carper's alternative quiet due to concerns that publicity could draw attacks from liberal activists, which could complicate efforts to line up support from the full Democratic caucus.
Given that Carper's plan -- which would create a series of state-level non-profit insurance carriers in states without competition -- is actually worse than co-ops (because they'd only be created in the case of a trigger), it's not surprising that Democrats would fear the reaction from liberals. No shock there.
But what is interesting is that they are afraid that pushback from progressives could scuttle Carper's plan to kill the public option. Even though they may be stupid enough to think that they can pull the wool over our eyes, they at least realize they need to keep us happy.
What's mystifying is that they would thinks a strategy of "shh, don't tell the progressives" is an effective way of accomplishing that.