We know that Stanley Ann and Hussein were world travellers but do we know if the Dunhams were as well? That could be very telling.
We know that her father was carousing buddies with Frank Marshall Davis after he moved to Hawaii. From Wikipedia, it says that Hawaii was suggested to Davis by his friend Paul Robeson, the famous singer and actor from the 1920s onward(see Showboat from 1936 with Irene Dunn). Robeson became a world-renowned communist.
Right there, Stanly Dunham was one or two steps away from some serious money. By then, Robeson had toured the world several times over doing theater and concert tours.
-PJ