It's Wednesday morning. House leaders have indicated they want to vote on both the Senate health care bill and amendments to it by Saturday night. But, as you may have noticed, they still haven't said precisely what the wording of those amendments will be. And that's because they still haven't finalized them.

It's not for lack of trying. In the offices of House Speaker Nancy Pelosi and Senate Majority Leader Harry Reid, and occasionally in other locations on Capitol Hill, officials and staff have been working furiously to work out terms acceptable to all of the different political and interest group factions. And they're long past arguing over the big picture, since the outline of the final compromise has been apparent for weeks: A bit more financial protection for individuals buying coverage, more financial assistance for seniors buying drugs, a slightly reduced tax on expensive health benefits, and a higher Medicare tax for wealthy people. This is what President Obama proposed two weeks ago and it is, more or less, House and Senate leaders had said they would support in early January.

But, as Lori Montomery explains today in the Washington Post, the devil really is in the details. And the devil, in this case, has a name: the Congressional Budget Office (CBO). In order to satisfy the requirements for the budget reconciliation process, through which Congress will consider the amendments, CBO must certify that the changes will reduce the deficit both in the decade following enactment and the decade following that.

By "reduce the deficit," I mean reduce the deficit relative to whatever the Senate health care reform bill would do on its own. And that is no small thing. The Senate bill, as written, was projected to save quite a bit of money. As such, the amendments must result in reform, as a whole, saving even more money than the CBO projected originally.

Accomplishing that in the first decade isn't so difficult. Basically, you figure out how much money it costs to improve the subsidies, to fill the Medicare drug donut hole, and to scale back the benefits tax. Then you increase the Medicare tax and maybe take a little more money out of the pockets of industry groups. It's more or less as simple as taking from column A and then pulling an equal amount, plus an extra billion or two, into column B.

But the second decade, apparently, is another story. Officials and staff aren't saying what the hang-up is; CBO, as a rule, doesn't comment. But it's safe to assume that it has something to do with the fact that small changes in the first ten years become much bigger changes in the second ten years, because of compounding effects. Remember, if you give people more financial protection against illness--a major goal of the amendments, not to mention reform as a whole--the economic models predict that, all else being equal, those people will consume more health care and, thus, spend more money. If revenue and savings don't keep up--don't forget, the Medicare tax doesn't rise with medical inflation the way the benefits tax does--then a financial gap will open up.

Whatever the issue with the accounting is, I imagine there are quite a few frustrated reformers sticking pins in their Doug Elmendorf vodoo dolls right now. (Devils, vodoo--I know, I'm mixing metaphors.) Pelosi has pledged she would post legislation at least 72 hours before she asks the chamber to vote on it. There's not much time left if she wants a vote by Saturday night, the target date everybody has in mind.

It's just a pledge, rather than a requirement. If necessary, leadership could always ignore it or post a full bill today and then tweak it a bit afterward. (That approach would seem completely reasonable to me.) But the longer it takes to nail down the CBO score, the harder it will be to get a vote by Saturday. And, of course, the longer Congress spends dithering, the more the story again becomes about process rather than substance--alienating the public all over again.

The cruel irony is that Democrats actually deserve some credit here. When President Bush and the Republicans wanted to pass their big health care bill, the creation of a Medicare drug benefit, they didn't even bother to pay for it. They were happy to run up huge deficits. When a government actuary predicted that the program would cost a lot more than its proponents claimed--a prediction that quite likely could have alienated enough conservative votes in Congress to stop the bill from becoming law--the Bush Administration ordered the actuary to say nothing and threatened to fire him.

Here, instead, we have President Obama and the Democrats confronting truly difficult trade-offs, in order to convince skeptical government accountants that health care reform will reduce government spending by even more than the accounts predicted it would already.

We hear a lot about the corrupt bargaining and backroom deals in health care reform. -There are valid reasons for that. But this is an instance where the Democrats are guilty of something else: Trying to practice good government.

Update: I fleshed out my explanation of what may be going on with the CBO score. Also, while I think reasonable people can disagree about whether CBO's accounting standards are too skeptical, they deserve credit for the herculean workload they've been shouldering. Politico has more on that.