Double irony: didn’t it finally emerge that Henry Wallace was a communist agent, and that was why FDR dropped him from the ticket?
He was definitely a Communist sympathizer and "useful idiot" but I don't think he was a formal Soviet agent per se. He served as Roosevelt's VP for a term but the Democrat Party named Harry Truman to replace him in the next election. Wallace later was the 1948 Presidential candidate for -- guess what -- the Progressive Party.