At the risk of repeating Andrew, I'm going to quote Ezra:
I'm also hearing a lot of irritation from congressional Democrats at the mixed signals being sent by the White House. If the White House wants to advocate for the trigger, fine. If the White House wants to advocate for the public option, fine. But for the White House to host one meeting where they signal that they're uncomfortable with Reid's decision to push the envelope on the public option and then make a big effort to walk that meeting back after the left gets angry is confusing everybody.
I don't really get the strategy here. It's like they want a public option but don't want to devote any nonrefundable political capitol to it. Or they don't much a care about a public option, and are scared to say so.