While AOPA and AMA are two different entities, the parallel is even more divergent than that... I am not FORCED to belong to AOPA if I wish to fly my Cessna, Piper, Maul, Beechcraft, etc. at a controlled field. In fact, AOPA membership isn't required for membership in flying clubs who are based at controlled fields. Fow what you pay, you get substantially more from AOPA than AMA, and that was the point being made.