The point that Chait makes here about how a lot of the nonsense about how tax cuts invariably lead to pony and unicorn explosions is borne out of the necessity of finding a politically palatable way of defending the principle that extremely wealthy people should have their taxes kept low is borne out by academic research. Mark Smith has a terrific book documenting evolving Republican discourse about taxes. In the 70s, Republicans generally made the case for massive upper-class tax cuts in relatively honest libertarian terms — and had very little success. But then they began to link massive upper-class tax cuts to economic growth, and met with much more political success. The only way to sell upper-class tax cuts is to pretend that they produce substantial collective benefits, and of course this requires a lot of distortion and lying since for the most part they don’t.