But when only one parent is legally recognized
This contradicts your premise so I don't know how you are proceeding with the argument.
The Constitution, nor any of the ensuing court decisions, mention legal marriage, only actual parentage and the Nationality of the parents.
What does moose cheese have to do with Gorebull warming?
AT THE TIME of his birth, obama’s mama didn’t meet the legal age to be outside the USA and give birth to a USA citizen, the law might have been changed, but AT THE TIME if she was outside the USA, her children WOULD NOT be legal citizens.
It is certain that a person born of two U.S. citizens is a "natural born" U.S. citizen as it pertains to Art. ll of the U.S. Constitution.
It is less certain that a person born under the jurisdiction of the United States of one parent is a natural born U.S. Citizen as it pertains to Art. ll of the U.S. Constitution.
I beleieve under to construct of my original post, Obama Jr. is a natural born U.S. citizen as it pertains to Art. ll of the U.S. Constitution.
ex animo
davidfarrar