 Rothenberg was a partner in the Los Angeles offices of the law firms Manatt, Phelps, Rothenberg & Phillips and Latham & Watkins, and in 1989–1990 he served as president of the California State Bar.Before his 2010 resignation, he was president of the Los Angeles World Airports Commission.In 2004 Rothenberg founded 1st Century Bank, a community bank with offices on the Westside Los Angeles area catering to small businesses and professionals.