Deliverance by James Dickey (in 2001, named as one of the 100 best English-language novels of the 20th century, as chosen by the editorial board of the Modern Library.)
... The left-wing of the SPA, or the Debs Caucus, including McReynolds, reconstituted the spirit of the SPA and Eugene V. Debs into the Socialist Party U.S.A. (SPUSA) that ...