'It's called birthright citizenship'
That is the 14th Amendemnt I think in about 1868. The rule about the Presidency was in about 1790 and then 1795 or something like that.
Here is Joseph Farah on why he thinks Rubio is not a "natural born citizen".
Before I briefly lay out the facts about Rubio's eligibility, let me make one thing clear: I really like Marco Rubio. I would vote for him for U.S. senator or for governor. I think he is an inspirational speaker. I agree with him on the big issues of the day. His life story is impressive. But his life story is also relevant to his eligibility status — and that cannot be ignored.
Mario and Oriales Rubio became naturalized U.S. citizens on Nov. 5, 1975, four years after Marco Rubio was born. That's really all you have to know. That simple fact — one not in dispute — disqualifies him legally, barring an amendment to the Constitution or a complete and deliberate misinterpretation of the Constitution, from being president or vice president. Those are the only two offices in the U.S. that have such a requirement.
The definition of natural-born citizen approved by the first U.S. Congress can be seen in the Naturalization Act of 1790, which regarded it as a child born of two American parents. The law, specifying that a natural-born citizen need not be born on U.S. soil, stated: "The children of citizens of the United States, that may be born beyond sea, or out of the limits of the United States shall be considered as natural born citizens: Provided, that the right of citizenship shall not descend to persons whose fathers have never been resident in the United States."
While the act was repealed five years later, it, nevertheless, represented the will of the Congress that someone with dual loyalties not lead the U.S.
Rep. John Bingham of Ohio, a principal framer of the 14th Amendment, affirmed in a discussion in the House on March 9, 1866, that a natural-born citizen is "born within the jurisdiction of the United States of parents not owing allegiance to any foreign sovereignty."
"The Law of Nations," a 1758 work by Swiss legal philosopher Emmerich de Vattel, was read by many of the American founders and informed their understanding of law later established in the Constitution.
Vattel specified that a natural-born citizen is born of two citizens and made it clear that the father's citizenship was a loyalty issue: "The natives, or natural-born citizens, are those born in the country, of parents who are citizens. 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. ... 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."
www.creators.com/conservative/joseph-farah/vice-president-rubio-not-so-fast.html