From the middle of the 19th century until the 1970s, about every serious health reform in the United States was due to the efforts of organized medicine. The American Medical Association, along with state and county medical societies, had a single, focused objective: replace a relatively free market for medical care with a cartel, fully protected by government regulation in every market that affected the economic wellbeing of doctors.
Whatever you think of their goals, you have to admire their methods. As I showed in Regulation of Medical Care: Is the Price Too High?, organized medicine understood economics and they used rational economic thinking in pursuit of all their political goals.