Donald Berwick informed his bosses that he plans to resign on Dec. 2 as Medicare administrator. He's leaving about a month earlier than expected. Berwick, a pediatrician by training, was a major get for the Administration. A Harvard professor, he founded the Institute for Healthcare Improvement, a think tank that trains hospitals on how to increase patient safety and improve operations. When the President picked him to run Medicare, it seemed like an obvious and perfect choice. The problem was his worldview. His approach to health reform, like the President's, promotes centralizing healthcare delivery and using government programs to force change. But once Congressional adversaries got a hold of some of Berwick's old writings, in which he had said nice things about the National Health Service in England, he became the subject of an ideological confirmation battle.