MEGAN MCARDLE: BUY NOW, PAY LATER:

If we pass this thing, no American politician, left or right, is going to cut any of these programs, or raise the broad-based taxes necessary to pay for them, without any compensating goodies to offer the public . . . until the crisis is almost upon us. I can think of no situation, other than impending crisis, in which such a thing has been done–and usually, as with Social Security, they have done just little enough to kick the problem down the road. The idea that you pass a program of dubious sustainability because you can always make it sustainable later, seems borderline insane. I can’t think of a single major entitlement that has become more sustainable over time. Why is this one supposed to be different?

Because they really, really want it.