 By September 1959 , it was clear that the Select Committee was not developing additional information to justify continued operation . A second interim report was released in August 1959 once again denouncing the Teamsters and Jimmy Hoffa . Robert F. Kennedy resigned as the Select Committee 's chief counsel on September 11 , 1959 , and joined Senator John F. Kennedy 's presidential campaign as campaign manager . Committee members became more involved in passing legislation to deal with the abuses uncovered . 
