[bert]

.....his second cousin.....

What is a second cousin? Can a bastard have a second cousin?

[Gumdrop]

Do you really want to know what a second cousin is?

1st cousins - offspring of siblings
2nd cousin - offspring of 1st cousins
3rd sousin - offpspring of 2nd cousins.

I assume this relationship if through Obama’s mother, Ann Benham,

Therefore, the doctors is the son of a 1st cousin to Ann Benham.

Another way to look at it is this: one of the doctor’s grandparents was a sibling to one of Obama’s maternal grandparents.

[Mercat]

Hit grandparent and one of Obama’s grandparents (the white ones) were siblings. For example, O’s white grandma, the one under the bus - maybe her sister’s grandchild would be Dr. Wolf.