OK. Read the article now.
Seems it wasn't Cranston, but the other California communist Senator Tunney.
Liberals are so disgusting.
Cranston was a good guess :-) He had a longer history with the antiwar movement than Tunney and brushed shoulders with CPUSA pretty often, but I haven't been able to document him actually working for the KGB. He and Tunney did work closely with the VVAW in the early 70s, though.