My colleague Neil Irwin has a very good piece on the difficulty the Congressional Budget Office has predicting the cost of something complex like the health-care reform bill. But because his piece is coming in the context of a coordinated conservative effort to discredit the CBO's analysis of the health-care reform bill, it's worth making a couple of points.

First, be very careful with any criticism of CBO that seems to be merited by a particular score rather than a particular methodological difficulty. To put that slightly differently, does anyone think that conservatives would be squawking if CBO had disappointed Democrats by saying the bill would save less money than either the House or Senate incarnations? If not, then keep in mind that this is a political, not...