Which is not the case here.
Indeed, it's not. Obama never qualified for birthright U.S. citizenship to begin with. He doesn't meet the 14th Amendment's requirements. See post 93:
http://www.freerepublic.com/focus/f-news/3011750/posts?q=1&;page=51#93
And his alien father was not permanently domiciled in the U.S. at the time of his birth per the U.S. v. Wong Kim Ark ruling.
It is possible that he may have naturalized as a U.S. citizen at some point after the time of his birth. However, naturalized citizens are ineligible to be President.
Gosh. How was I certain that this topic revolved around Obama. Quel surprise.