That particular instance in August of 1939 was Sen Pepper and Sen Downey berated other Dems and the GOP.
Claude “Red” Pepper was a one-time admitted Communist Party supporter. His name appeared on a lot of CPUSA front letterheads and in support of causes during the 30’s and 40’s.
He got religion when Florida got a lot of anti-communist refugees who became voting citizens. He then became “anti-communist” in order to save his seat in Congress.
Lot’s of history to this man. Others from that era who were “party” in support if not actual membership (covert) included Sen. Metzenbaum and Sen. Cranston (who were more a Soviet agent of influence than just a Party hack).