“His was an American character, one typical of men of his generation, men who embraced the notion of freedom and individualism and the open road without always knowing its price, and whose enthusiasms could as easily lead to the cowardice of McCarthyism as to the heroics of World War II. Men who were both dangerous and promising precisely because of their fundamental innocence; men prone, in the end, to disappointment.” - Barack Obama, Dreams of My Father
JDno one of these people should be able to give you the research links you ask about.
IIRC His grandparents attended “The Little Red” church on Mercer Island and were friends with known communists in HI.