Matthew Yglesias seems a bit puzzled that Democratic party elders haven’t stepped in to force Hillary Clinton out of the race. He writes that “insofar as it’s really true that [Nancy Pelosi] and ‘other leading members of Congress’ think [don’t think Hillary can win and want her to give up], they need to communicate it more clearly.”

By contrast, Marc Ambinder suggests that party elders have intentionally decided not to step in because “in their minds, the racetrack is open and horses, to beat that metaphor to death, are still trotting around” (via Michael Crowley):

John Edwards, Al Gore, Nancy Pelosi, Harry Reid – if these folks came together and threw their weight behind the nominee, Hillary Clinton would probably drop out by the end of the week. But the party elders have in some cases explicitly abstained from making such a determination because in their minds, the racetrack is open and horses, to beat that metaphor to death, are still trotting around.

But there’s actually a third possibility — that most party elders would prefer that Hillary withdraw but don’t want to pay the cost of pushing her out of the race. There are two classic economic problems here. The first is that the collective benefits of pushing Hillary out are much larger than the individual benefit to any one party leader (i.e. there’s a positive externality). Why would Pelosi or Reid risk becoming a hated figure to millions of Hillary’s supporters? As a result, everyone is likely to sit back and hope that someone else will pay the cost of forcing her out.

The second problem is it’s difficult to coordinate a joint effort to push her out. In other words, there’s a collective action problem. If all the leaders could magically come together to ask her to withdraw, it might be less costly to them individually to push her out, but any effort to make this happen would inevitably leak, generating untold recriminations and infighting. The incentives to defect from such an agreement would also be strong. As a result, no one is likely to chance it.

For both of these reasons, it’s likely that the race will go to the convention unless (a) Hillary decides to withdraw on her own or (b) the accumulation of superdelegate commitments after the primaries drives her out.

Update 3/25 10:01 PM: TNR’s Noam Scheiber outlines the possible scenarios in a recent piece — the key quote to me is in bold:

Democrats have never been known for Spock-like rationality, but even they see the logic of avoiding a convention fiasco. “It’s in nobody’s interest in the Democratic Party for that to happen,” says Mike Feldman, another former Gore aide. “There is a mechanism in place–built into the process–to avoid that.” That mechanism, such as it is, involves an en masse movement of uncommitted superdelegates to the perceived winner of the primaries. Almost everything you hear from such people suggests this will happen in time. “I think once we have the elected delegate count, things will move fairly quickly, ” says Representative Chris Van Hollen, who oversees the party’s House campaign committee. Increasingly, there is even agreement on the metric by which a winner would be named. Just about every superdelegate and party operative I spoke with endorsed Nancy Pelosi’s recent suggestion that pledged delegates should matter most.

Assuming Feldman and Van Hollen are right, that means Democrats won’t wait much past June 3–currently the last day on the primary calendar–before crowning a nominee. At the same time, it means there’s very little chance of ending the contest sooner. Undecided superdelegates on Capitol Hill, along with party elders like Pelosi, Gore, and Harry Reid, “don’t want to be seen as elites coming in and overturning the will of the people,” says one senior House aide. A Senate staffer says his boss “thinks this give and take is natural, it will be helpful in the end.” “That’s a view held by a majority of these guys who have been through the cut and thrust of politics,” he adds. Which means early June it is.

…The most optimistic scenario I could plausibly construct didn’t end the campaign until the second week in May. To make it happen, Obama would have to overtake Hillary among superdelegates–a key psychological barrier. He’d have to limit his margin of defeat in Pennsylvania to ten points, then hold serve two weeks later in North Carolina and Indiana, a pair of states he’s slightly favored to win. At that point, Hillary would face nearly impossible odds of overtaking him in the delegate race.

Unfortunately for anyone who wants the race to end soon, there are several problems with this scenario. For one thing, even if all this comes to pass, Hillary would still have to bow out voluntarily–an unlikely twist in any event, but highly implausible if the limbo states of Florida and Michigan still offer her hope. Meanwhile, any one of the aforementioned steps could easily fall through. Polls currently show Obama trailing by double digits in Pennsylvania; the good Reverend Wright could make that tough to change. And, though Obama now leads in North Carolina and Indiana, his advantage is either small or, in the latter case, based on a single, flimsy poll. As for superdelegates, as of this writing, the last two out of the closet opted for Hillary.

So, to review: The most optimistic scenario we have relies on a highly tenuous assumption; it’s unlikely to happen even if that assumption holds; and, regardless, it allows the Democratic contest to drag on for six more brutal weeks. The dream may never die, but it’s seen some better days.

Update 3/26 8:29 PM — Note how Harry Reid is also dodging responsibility for settling the issue in this interview (via Kevin Drum):

Q: Do you still think the Democratic race can be resolved before the convention?

Reid: Easy.

Q: How is that?

Reid: It will be done.

Q: It just will?

Reid: Yep.

Q: Magically?

Reid: No, it will be done. I had a conversation with Governor Dean (Democratic National Committee Chairman Howard Dean) today. Things are being done.

In this context, “[t]hings are being done” means “we’re all trying to get someone else to do the dirty work.” I’m not sure we should believe him — Howard Dean doesn’t want to alienate half the party either.

Update 3/27 9:11 AM — In comments, Jesse Einhorn questions my claim that “The incentives to defect from such an agreement would also be strong,” asking “[w]hat possible incentive would there be to defect back to Hillary’s camp” from a possible joint effort to push her out given that she is extremely unlikely to win. However, my claim isn’t that the leaders would “defect… to Hillary’s camp” but that they would defect to a position of neutrality. Expect lots of mumbling about letting the process go forward, etc etc. The reason to do this that, while Hillary is likely to lose, her supporters (financial, activist, etc.) are and will remain powerful within the party. If you don’t believe me, ask Nancy Pelosi, who just got an ominous letter from Hillary’s top fundraisers:

We have been strong supporters of the DCCC. We therefore urge you to clarify your position on super-delegates and reflect in your comments a more open view to the optional independent actions of each of the delegates at the National Convention in August. We appreciate your activities in support of the Democratic Party and your leadership role in the Party and hope you will be responsive to some of your major enthusiastic supporters.