Numerous politicians became his fans, with John F. Kennedy asking him to write his jokes for campaign speeches. After Kennedy's assassination in 1963, Sahl focused on the Warren Report's inaccuracies and conclusions, and spoke about it often during his shows. This alienated much of his audience and led to a decline in his popularity for the remainder of the 1960s. By the 1970s, however, his shows and popularity staged a partial comeback which continues to the present. A biography of Sahl, "Last Man Standing", by James Curtis, was released in 2017.