Well isn’t this interesting:

Sen. Joe Lieberman has reached a private understanding with Majority Leader Harry Reid that he will not block a final vote on healthcare reform, according to two sources briefed on the matter.

Chris Bowers asks what people think the “private understanding” is.  Booman guesses that Reid threatened Lieberman with taking away his position as Homeland Security Committee Chair if Joe voted against cloture at any procedural point in the Senate debate.

Lieberman would have to get something in return for not voting against cloture on a health care reform bill he opposes. Keeping his Committee chairmanship, something that Lieberman has repeatedly bet he could do anything to retain (remember, he campaigned for John McCain), isn’t likely to be considered something by Joe Lieberman. He thinks he owns it already and there has been essentially zero will publicly expressed by the Democratic Senate caucus towards removing Lieberman from his chair as a consequence of his actions.

It’s also worth pointing out that while Lieberman has already said he won’t oppose a Motion to Proceed to the bill and sources are now saying he won’t oppose cloture on final passage, there is a third major cloture vote that has not yet been discussed. As I wrote on the SEIU blog, there is a cloture vote on the manager’s amendment to substitute the debated and amended healthcare bill onto a bill from the House Ways and Means Committee.

Cloture Motion on Manager’s Amendment (Substitute Amendment): After considerable debate and amendment to the substitute, the Majority Leader will file Cloture on the Substitute. If there are 60 votes here, the Merged reform bill/Substitute as amended will get an up or down vote after 30 hours of post cloture consideration.

So, in some sense, it seems that both Senator Lieberman and Leader Reid are weaseling on process questions right now. At least, neither are speaking publicly about Lieberman’s expected stance on the cloture vote that will occur between the Motion to Proceed and the cloture motion on final passage of the measure.

Getting beyond the weaseling on process, I don’t know what Lieberman is seeking to extort from Reid. Job security is clearly something he already thinks he has in the bank. More job security would certainly be helpful for Joe, but would it really be enough for him to vote with the caucus on procedural votes that he already sees as tantamount to the substantive vote on the bill itself on final passage?

Lieberman’s real problem is with the public option. Perhaps what Reid promised Lieberman was an opportunity to vote on an amendment to remove the public option from the bill, with a threshold of only 51 votes. This would increase the likelihood of it getting stripped out, as well as the likelihood that Lieberman will actually vote with the caucus on all cloture votes (as he said he would if he was happy with the underlying bill). The flip side, obviously, is that if Reid were to push for a 51 vote threshold for an amendment to strip the public option in the Unanimous Consent agreement governing the debate, he would essentially be guaranteeing its removal from the bill, after showed rare leadership by fighting alongside Chris Dodd for its inclusion.  If this is the case, expect a huge uproar from the people who have worked to get the public option as part of health care reform legislation.

Of course, I think Open Left commenter bento is probably most right about what the private understanding means: “Reid, in the privacy of his head, understands Lieberman will not filibuster. Joe in his privacy understands he will. ”

Update:

Lieberman spokesman Marshall Whitman has strongly denied the reporting of a “private understanding” in a quote to the National Review.

…Adding, Reid’s office is now denying the report of an understanding as well.