Yeah so since NBC isn't defined, how can Obama be one? Use the liberal theory of anyone born that survived abortion? By the way IMO Obama should be the poster child for Pro-Choice, his mama made some bad choices and we are paying the price.
Because he was born here. And the 14th Amendment and federal law both state that anyone born in the U.S. is a citizen from birth. Since the Constitution only identifies two types of citizenship - natural-born and naturalized - then if you're not one you are the other. He's not naturalized so that narrows things down, doesn't it? And if the Constitution is 'liberal theory' then that doesn't say much for conservatives, does it? Should be the other way around.
Qualifications for the Office of President
Age and Citizenship requirements - US Constitution, Article II, Section 1
No person except a natural born citizen, or a citizen of the United States, at the time of the adoption of this Constitution, shall be eligible to the office of President; neither shall any person be eligible to that office who shall not have attained to the age of thirty-five years, and been fourteen years a resident within the United States.
Term limit amendment - US Constitution, Amendment XXII, Section 1 – ratified February 27, 1951
No person shall be elected to the office of the President more than twice, and no person who has held the office of President, or acted as President, for more than two years of a term to which some other person was elected President shall be elected to the office of the President more than once.
http://www.presidentsusa.net/qualifications.html