Sam Dewitt is most famous for being expelled in 1920 from the New York State Assembly along with four fellow assemblymen for being members of the Socialist Party. The five Socialists were barred from taking their seats at the beginning of the session of the 143rd New York State Legislature and, after a protracted "trial" before the Assembly Committee on the Judiciary, defended by Morris Hillquit and Seymour Stedman, were expelled on April 1. All five were re-elected at a special election on September 16, and appeared to take their seats at the beginning of the special session on September 20. The next day, DeWitt and Samuel Orr were permitted to take their seats, but August Claessens, Charles Solomon and Louis Waldman were expelled again. Protesting against the re-expulsion of their comrades, DeWitt and Orr resigned their seats.