Herndon was defended by the International Labor Defense, the legal arm of the Communist Party, which hired two young local attorneys, Benjamin J. Davis Jr. and John H. Geer, and provided guidance. Davis later became prominent in leftist circles. Over a five-year period, Herndon's case twice reached the United States Supreme Court, which ruled that Georgia's insurrection law was unconstitutional, as it violated First Amendment rights of free speech and assembly. Herndon became nationally prominent because of his case, and Southern justice was under review. By the end of the 1940s he left the Communist Party, moved to the Midwest and lived there quietly.