“Don Berwick – who, as administrator of the Centers for Medicare and Medicaid Services, oversaw large chunks of the early implementation of the Affordable Care Act – is trying to shake up the health policy world again. He ran CMS from July 2010 to December 2011, and left because Senate Republicans blocked his confirmation to lead the agency permanently. Now, more than two years later, he is a long-shot Democratic candidate for governor of Massachusetts and the heart of his platform is a single-payer health plan.”