I keep reading that or variations of it over and over - yet how does that make it any more true? In the year of his birth, one didn't require both parents to be US Citizens for the child to be an automatic citizen (natural born).
“Citizen at birth” and “natural born citizen” are not interchangeable or synonymous.
You can find the information on FR if you’re interested.
http://www.freerepublic.com/~rxsid/
Scroll down and pay special attention to what John Bingham had to say. He is the father of the 14th amendment.