All good points, and 923 did a good job summarizing, because this is slightly shifting the goalpoasts. Because as health spending was dropping, why wasn't the CBO accounting for it with its ten-year projections circa 08-10 when the aforementioned GOP loonies were saying the sky was falling? And the chart of slowing per-beneficiary growth is for A and B, not D, which was the focus here, and Krugman's postulation. He perhaps takes his thesis too far in suggesting a Medicare miracle or in wanting to give all of the credit to Obama for something (CBO projection) he had little to nothing to do with.
My continued point has only been that the sky was never falling.