More than 30 years ago Dr. Donald Berwick began seeing patients in the Martha’s Vineyard Hospital emergency room. At the time, the ER was staffed by visiting physicians on weekends, so he helped set up the schedule and find the doctors a place to stay for the night. Since then, he has stopped seeing patients, was temporarily appointed by President Obama as administrator of the Centers for Medicare and Medicaid Services in Washington, D.C., and in June, declared his campaign for governor of Massachusetts.