If Harry Reid were Jerry Seinfeld, he'd probably be snarling the name "Lieberman" through gritted teeth right now, in true Newman-esque fashion. The Connecticut senator announced this afternoon that he'll join a Republican filibuster of the health-care bill unless the public option provision is changed. In doing so he's effectively cleared the way for other fence sitters, like Evan Bayh, Ben Nelson, and Blanche Lincoln to do so as well, and avoid taking as much heat.

When Lieberman, who is technically an Independent, came back to the Democratic caucus after deserting it in the 2008 election, he could have been stripped of his committee assignments as punishment for his infidelity. That's what any party who understands a thing or two about political discipline might be expected to do. But we're talking about Senate Democrats here, so of course Lieberman got a light rap on his knuckles. He lost his spot on the Environment and Public Works Committee, but he retained his coveted position as Chair of the Senate Homeland Security Committee. President Obama was a key Lieberman supporter, encouraging Democrats to let bygones be bygones. That was the heady aura of D.C. just 11 short months ago. A new kind of politics. Post-partisanship. Change we can believe in and all that. But Lieberman's actions today demonstrate that no good deed goes unpunished. I'm sure many Democratic senators are wishing right now they could take that vote over. They're probably reminiscing fondly about Ned Lamont.

Democrats shouldn't be surprised though. This is what happens when there's no price to pay for disloyalty. What's Lieberman got to lose? He can spend the better part of a presidential campaign trashing the Democratic nominee and yet be welcomed back into their caucus. What's his motivation to start acting like a dutiful caucus member? That would only diminish his now-considerable power as both a committee chair and vote-hedger. To be fair, Democratic motivations weren't entirely altruistic either. Forgiveness was probably less a consideration than having an opportunity to exert pressure on Lieberman in the caucus room, and count him among their 60 precious votes. Leadership knew health care was on the agenda this year, and they would need his vote. Better not make him cranky. Besides, Lieberman's most prominent splits with Democrats have been over foreign policy and national security, where he's long been closer to McCain's positions. On health-care reform, he'd probably be right at home in Democratic caucus, right? Um, wrong.

So what is Lieberman up to exactly? In some respects, his words are a little vague. Here's what he said today via TPM:

I've told Sen. Reid, that I'm strongly inclined, I haven't totally decided but I'm strongly inclined to vote to proceed to the health-care debate even though I don't support the bill he's bringing together, because it's important that we start the debate on health-care reform because I want to vote for health-care reform this year. But I also told him that if the bill remains what it is now I will not be able to support a cloture motion before final passage. Therefore I will try to stop the passage of the bill.

And from Politico:

I can't see a way in which I could vote for cloture on any bill that contained a creation of a government-operated-run insurance company ... It's just asking for trouble—in the end, the taxpayers are going to pay. 

So, he'll let the bill come to the floor for debate, but won't vote to end debate and allow the bill to be voted on, unless the bill changes. Well, no doubt there will be amendments and changes to the bill before it is voted on, so he's given himself some wiggle room. He says he doesn't want a public option, but hasn't gotten into specifics about what he could accept, so maybe he has some room to move there too.

Bear with me here while I get a little speculative, but perhaps he's playing a different game entirely. It's within the realm of possibility that he is signaling to the more liberal House Democratic caucus not to get carried away. Once the Senate passes its bill, it will have to be reconciled with the House version in conference. That conference report then has to be approved by both chambers in a simple up or down vote, no amendments. This might be a bit of a stretch, but perhaps what Lieberman is really trying to do is to scare House Democrats, warning them not to push for a more robust public option in the final version. If they do include include the sort of plan that would satisfy House liberals, Lieberman will have no qualms about voting that down, killing the entire enterprise. He's set himself up nicely to do that.

But maybe I'm giving Lieberman too much credit for developing long-term negotiating strategy. Maybe he's prepared to kill any bill containing a form of public option, strong or weak. And if that's the case, Democrats need to seriously think about whether he should be allowed to remain in the caucus. Remember, the public option is just one part of a large-scale restructuring of health-care provision in the U.S., even if it does receive disproportionate attention in the debate. The bill also aims to extend insurance coverage to a significant number of poor Americans, make health care more affordable, and prevent insurance companies from denying care or dropping members. If Lieberman (and let's not forget Bayh, Nelson, and Lincoln here) is prepared to sacrifice all of that because they don't like a public option that will only be available to small, select groups of people in states that wish to participate in the plan, then surely the question has to be raised: do you really belong in this caucus room?