Yup. It’s all covered in Obamanutz:
http://joytiz.com/obamanutz-a-cult-leader-takes-the-white-house/
Some very peculiar relationships.
I'm very much aware of "cousins" in that coterie maintaining contact over the generations ~ and to a degree that's very smart because it keeps them in touch with the money AND the easy way to get into Ivy League schools.
They spotted several other colonies around the country in later years (as tobacco growing expanded into new lands).
The girls still go back to St. Mary's to go to college. The young men still meet the girls who go there.
Marriages are made. Babies happen.
And all of them are related to the Smallwood clans hither and yon.
They are not as numerous or well-known as the Dunham crowd, but they exist.
There are others that've managed to maintain their roots over the centuries.
OH TY.