Mary Landrieu (D-LA) was one of the Senators to watch for opposition to the Senate health care bill. She has been a staunch opponent of the public option as recently as two weeks ago, and she certainly didn’t sound like someone inclined to go along with whatever the Senate would put out.

This morning, Landrieu participated in a press event promoted by the Senate leadership discussing the impact of health care reform on small businesses. Landrieu is the chairwoman of the Small Business Committee in the Senate, so she has every reason to be there, but her presence at an event basically touting the leadership’s health care bill is quite a turnaround. And last week, Landrieu signed on to a letter from Ron Wyden (D-OR) calling on Harry Reid to open up the exchanges and allow more people to choose the plans there, including the public option. I think we can take the Senator’s participation as a sign that she will not vote to obstruct the bill in any major way.

With Landrieu and Evan Bayh apparently on board, the list of potential problem children in the Democratic caucus on health care appears to have narrowed to a few: Blanche Lincoln (who’s meeting with the President today), Ben Nelson and Joe Lieberman.

UPDATE: Brian Beutler also notes the tension between Landrieu’s appearance and her past statements. She apparently said at the event, “Doing nothing is not an option.” That will be a memorable line if she decides to vote to obstruct.