Please read these thoughtful and reasoned articles regarding the definition of a “Natural Born Citizen”. Truth is truth, take it or take it.
Note: This is NOT to be confused with the birth cert. issue.

The Constitution, Vattel, and “Natural Born Citizen”: What Our Framers Knew By Publius Huldah, 07.19.12, and an article he links to:
ROMNEY, RUBIO, McCAIN AND NATURAL BORN CITIZEN By J.B. Williams, 06.11.12
Among the references cited: the lexicon in the days of our founding (Vattel’s Law of Nations), the language of the First Congress in the Naturalization Act of 1790, and even the current-day resolution in the U.S. Senate which cleared John McCain to run for President.

Conclusion:

“Natural Born Citizen”: Child born of a father who is a citizen.
Barack Hussein Obama: At birth, his father was NOT a U.S. citizen, but a subject of the British Crown.
Marco Rubio: At birth, his father was not a U.S. citizen, but a citizen of Cuba.

This is not to imply that these men are not U.S. citizens, but rather points out that they were not naturally born so, thereby making them ineligible for the office of President of the United States, as set forth in Article II, Section 1, Clause 5 of the Constitution.

These articles also debunk the whole “Anchor Baby” lie that foreigners giving birth in the U.S. somehow bestow U.S. citizenship upon these children.

I recommend you read both of these articles with an open and sober mind. ~tdv