The term SEN. FEINSTEIN is a reference to DIANNE Feinstein, an American politician who has served as a United States Senator from California since 1992. She is the longest-serving female senator in U.S. history and the first woman to serve as the President pro tempore of the United States Senate. Feinstein was also the first woman to serve as mayor of San Francisco, a position she held from 1978 to 1988.