He was chosen as a floor reporter for the 1952, 1956 and 1960 political conventions. After Leonard was promoted to correspondent, Fred W. Friendly chose him for the CBS Reports team. He led CBS' new news election unit from 1961 to 1965 and helped develop exit polling. He then held a series of management positions at CBS News, rising to President in 1979 until his 1982 retirement. As president, he chose 60 Minutes correspondent Dan Rather to succeed Walter Cronkite as anchor of the CBS Evening News in 1981. He also created Sunday Morning. Leonard and Chairman William S. Paley were the only two employees allowed to stay on past CBS' mandatory retirement age. He was the stepfather of journalist Chris Wallace.