Jane Hamsher was on Rachel Maddow's show talking about Joe Lieberman's announcement that he would filibuster health care reform if the legislation included a public option. As Jane points out, this is brings up the question of whether it actually means anything that the Democrats have a so called filibuster proof majority in the Senate. After all, if Harry Reid isn't able to get his caucus to prevent Republican filibusters then we don't actually have a filibuster proof majority.
What I think's worth noting here is that a lot of people won't blame Lieberman for preventing this legislation from moving forward. In the end, if there is no meaningful health care reform that's passed, all many voters will remember is that Obama and the Democratic leadership were unable to get the legislation passed. It's therefore in the White House's best interest to make sure that Lieberman votes for cloture.
Furthermore, Obama most definitely has the upper hand in negotiations with Lieberman on this issue. In addition to having the bully pulpit of the White House when trying to get Lieberman's vote, Obama also can remind Lieberman of the fact that he stood up for the Senator when many Democrats were considering stripping him of his Chairmanship of the Homeland Security Committee. Harry Reid has taken the step of presenting a bill to the Senate floor that includes a public option and now the White House has a responsibility to work with him to ensure that health care reform is allowed an up or down vote in the Senate.