Obama’s father was not a citizen.
Obama’s mother was not 21.
The ruling Sloth posted overrules your example.
It’d be interesting to see this argued before the Supremes. It still seems like a big grey area and very subjective. Personally, I think they’d side with Obama’s being qualified, even if born in a foreign country, simply due to the status of his mother. It would raise many problems if young female American citizens had citizenship questions about children born either in or out of wedlock, fathered by foreign nationals, at least leaving them in limbo. It seems common-sense here. If the mother is an American citizen, unless she has renounced her citizenship, it shouldn’t matter where the child is born, as the child would still be considered a citizen of the U.S. (and hence, qualified to run for President).