The divide between health care supporters and health care opponents on the President's introduction of his health care bill and embrace of reconciliation is stunning. Liberal supporters like Paul Krugman and Jon Cohn are ecstatic, and see victory on the horizon. Opponents like Perrin and Megan McArdle have a "yeah, right" take on this.

The truth is probably somewhere in the middle. I think that the odds on the current plan passing are somewhere around 50-50, without enough information to determine whether the probability distribution skews positive or negative (though I suspect positive).

On a rational level, the "no way this passes" arguments have the better of it. Setting aside the procedural headaches -- and I think most of what Obama has proposed probably CAN be done with reconciliation -- the whip count is daunting. There are probably 50 Democratic Senators willing to vote for the reconciliation "sidecar," which pulls the plan somewhat to the left. That allows nine Democrats to vote for the plan before they vote against it, and the bill still passes. The best thing that Democrats have going for them here is that there are only two Senators from red states up for re-election this year, and one of them is retiring. If this were happening in 2012 or 2014 I'd say "no way." But in 2010 it might work; it is easy to see 50 Democrats say (a) I really want this to pass, even if it kills me politically, (b) I think public opinion turns around on this by the time I'm up, (c) I'm at 30% in the polls already, so I'm dead meat either way, so let's hope for a nice Administration position and/or (d) I'm from Rhode Island, so this will help me.

It is a different story in the House, where everyone is up this year. The House passed the bill back in those bygone days when Obama's approval rating was plus ten in the RCP average, as opposed to plus 1.6 today, and when polling on the bill still occasionally showed more people in favor of the bill than opposed (only two polls, which were taken of all adults rather than voters, have shown only single digit opposition since mid-January).

Let's assume for a moment that the decline in the bills' fortunes alone won't cause any "yesses" to flip to "noes." For this to occur, the "you've already voted for it, so you may as well go all-in" argument would have to carry the day. I think it's a ludicrous argument -- to paraphrase Megan McArdle, it's like arguing that if your significant other catches you kissing someone, you may as well decide to go all the way since you're likely heading for a breakup anyway. And while John Kerry's "I voted for it before I voted it against it" is a line that will forever go down in political infamy, what caused the most damage to Kerry was that he was trying to own the "I voted for it" portion after voting "no" (the rare flip-flip flop!), not that he changed his mind. But let's just assume that there aren't any flips away from the bill due to the decline in the bill's fortunes.

The bill passed the House 220-215. Jack Murtha has died, Robert Wexler has left Congress, and Anh Cao has changed his vote. That puts the vote at 217-216. The "X" factor here is the Stupak caucus. There are purportedly ten Democrats that only came on board in November with the addition of Stupak. Let's assume half of those are sincere -- and I think "they've added federal funding of abortion" would inoculate most of these members from the "flip-flopper" argument. That puts the bill in a four-to-five vote hole. Given the decline in the fortunes of the bill since November, and the fact that Pelosi almost certainly wouldn't have accommodated Stupak if she had many votes to play with in the first place, that should be the end of the bill (note also that few commentators who argue that it would be deadly to flip from "yea" to "nay" on the bill acknowledge that a few members will probably have to flip from "nay" to "yea" to pass the bill).

But that analysis assumes that we're proceeding on a rational level. The history of this bill, however, has potentially singlehandedly ruined the careers of political scientists who have insisted that politicians are rational actors whose number one priority is re-election. There's no way that Ben Nelson or Blanche Lincoln should have voted for this bill. It was what lawyers in my old law firm used to affectionately call a "CLM," or "career-limiting move." But for whatever reason, be it a genuine belief in the bill or a decision that voting nay would result in worse reprisals than would voting yea, they voted yes.

In the end, I suspect there's a very real likelihood that we'll see the same dynamic play out in the House. For one thing, there are a handful of Democrats who voted "no" before who are retiring rather than face re-election. While I don't think all of them can be flipped (did Marion Berry sound like he wanted to play ball with Obama in his retirement speech?), one or two probably can. I would also guess that in the month since Scott Brown's victory in Massachusetts, the White House has been sending out feelers to the House and Senate leadership, to see if the approach was do-able. If this wasn't at least do-able, I don't think they'd have gone all-in like this.

So who would I keep an eye on? Democrats who voted "no" from marginal districts (not heavily McCain districts), especially those from Northern districts. My short list: Adler (NJ-03), Baird (WA-03) (ret.), Boccieri (OH-16), Gordon (TN-06) (ret.), Kosmas (FL-24), Kucinich (OH-10), Massa (NY-29), McMahon (NY-13), Murphy (NY-20), Nye (VA-02), and Tanner (TN-08) (ret.). If you see a few of these members sign on to Obama's bill, then I think it really is "game on."