The Democrat party has a strong thread of communist/socialist/fellow travelers all the way back to John F Kennedy. Unions have had the same threads to communism only they go back further.
Henry Wallace FDR’s VP..
Even more damage was done to Wallace’s campaign when several prominent journalists, including H.L. Mencken and Dorothy Thompson, publicly charged that Wallace and the Progressives were under the covert control of Communists.
http://en.wikipedia.org/wiki/Henry_A._Wallace