Marc Ambinder has more on the White House meeting with health care industry stakeholders, including this key passage: 

This convention has been in the works for a week, and its existence has been a secret of sorts even to many White House officials. The worry was that if news leaked that these groups were going to participate, they'd receive intense internal pressure--or pressure from their ideological compatriots--to withdraw their participation.

Focus, for a moment, on the possibilty of "internal pressure" the groups might have faced if word of the meeting had leaked out. This is one of the most underappreciated aspects of Washington politics.

We tend to think of interest groups as monoliths. The insurers. The drug industry. The unions. But each interest group has its own internal dynamics. The leadership may pull in one direction while the members pull in another. At the same time, elements within either the leadership or rank-and-file may argue among themselves.

And that's been happening this year over health care, as Marc suggests. If you talk to the Washington lobbyists for major trade groups, on the right and (to a lesser extent) on the left, you hear a lot about how they are trying to "educate" their members and bring them along. The implict conceit is that these lobbyists think there's a deal to be had--one worth making--but that they'll have to overcome the instinctive resistance of their rank-and-file.

Whether this is a good or bad thing, naturally, depends on where you lie on the philosphical spectrum, whether you believe what these folks are saying, and so on.

But, as you try to game out what might happen in the health care debate, it's important to remember that the lobbyists and spokespeople for interest groups have their own constituences--constituencies that they can try to lead, but sometimes will follow, for better and for worse.

--Jonathan Cohn