The AMA controls medical school certification, and size, and therefore controls the number of new entrants, keeping earnings high. It doesn't organize medical

The AMA controls medical school certification, and size, and therefore controls the number of new entrants, keeping earnings high. It doesn't organize medical doctors for working conditions, salary and benefits negotiation, insurance, or most of the other features of a union. A hospital chain doesn't negotiate with the AMA on behalf of their surgeons and hospitalists. (It would probably be a very good thing if interns and early residents had a union supervising working conditions.)