They argue that eventually we will need government rationing of health care. But they say that this issue can be deferred, because in the short run the shift to a government-run health care finance system would save enough money to allow us to continue to afford premium medicine.
Krugman and Wells believe that the efficiency of socialized medicine is a sure thing, and that health care rationing is a far-off possibility. In fact, if the United States were to adopt government-financed health care, the results would be the reverse. Efficiency would fail to improve, and instead it would most likely deteriorate. Rationing would be a sure thing.
I don't think that there is a sensible economist out there who would bet more than a nickel of his own money on his or her estimate of what single-payer health care would do to efficiency (meaning the ability to deliver the same health care procedures at lower cost). The evidence that we have is very mixed. Yet Krugman writes as if large gains in efficiency are a moral certainty.