Other Democrats seeking the nomination include Mark Green , a former public advocate of New York City ; Assemblyman Richard L. Brodsky of Westchester County ; Charlie King , the head of a nonprofit organization that provides housing to homeless people ; Assemblyman Michael N. Gianaris of Queens ; Sean P. Maloney , a lawyer who worked as an aide to President Bill Clinton ; and Denise O'Donnell , the former United States attorney for the Western District of New York .