Diane Rehm has been on the air for nearly 30 years. She plans to retire at the conclusion of the next presidential election. “The Diane Rehm Show” is a two-hour program heard on 197 public radio stations reaching about 2.5 million people every week. It originates from radio station WAMU on the campus of American University. Rehm who is now 79 years old began her career as a volunteer at WAMU in 1973. Six years later she took over hosting duties of its mid-day show, which was then called Kaleidoscope. It was renamed for its host in 1984.