Vattel’s Law of Nations:

“As the society cannot exist and perpetuate itself otherwise than by the children of the citizens, those children naturally follow the condition of their fathers, and succeed to all their rights. The country of the fathers is therefore that of the children; and these become true citizens merely by their tacit consent. I say, that, in order to be of the country, it is necessary that a person be born of a father who is a citizen; for, if he is born there of a foreigner, it will be only the place of his birth, and not his country.”

Every Supreme Court Justice knows what the term means, which is why the Supreme Court prefers to never hear the case. The term Natural Born Citizen refers to a citizen by Natural Law (aka the Laws of Nature), the natural offspring of a Father who was at the time of the child’s birth, a legal Citizen of the United States. The nation of the Father is thereby the nation of the child, via Natural Law.

Link: Lex Greene -- Natural Law and Natural Born Facts

Since Romney and Rubio's fathers where citizens at the time of his birth in the US, that makes them "natural born citizens" IAW Natural Law, where on the other hand, President Obama's father clearly was not a citizen at the time of Obama's birth, thererore making him not eligible for the Office of the President. Seems that a judge up in Georgia will decide this question shortly. To bad that there is no main stream media coverage of this proceedings. Wonder how long that judge will have that judgeship?