The essential fact is Obama’s In-your-face admission that he was “born a dual-citizen”, of England and the U.S. He is boldly saying, I'm not eligible by the old rules, the Constitution, but they are historical artifacts. I'm half black and you wouldn't dare discriminate against a black man, would you?
The definition of a natural born citizen, cited in a dozen cases, most clearly by Minuteman and third chief justice John Marshall in The Venus, 12, U.S. 253 “...born in the country of citizen parents”. This definition has never been altered, and was quoted by Patrick Leahy, Clair McGaskill, Hillary Clinton, et. al. in Senate Resolution 511, Apr 2008, as they tried to insure that their opposing candidate would be John McCain, who had his own natural born citizen problem, thus providing cover for Obama. Don't be fooled by Leahy's legalese disclaimer that natural born citizen has no definition in the Constitution. He knew this day might come, as did all senators, and Michael Chertoff, who made the same assertion about McCain "Because both of his parents were citizens ... he is a natural born citizen". According to Alexander Hamilton, Vattel is part of U.S. Common Law, fully part of our constitutional foundation. Marshall, Waite and Bingham all cite Vattel's Law of Nations.)
No society would or did guarantee allegiance, the qualifications for our "King" and commander of our military, the founding credentials of a nation to the child of a father who opposed our ideas - a non-citizen. That is called jus sanguinis. It has origins at least in Roman law, and was the rule for France at the time of our revolution. Vattel, who codified the ‘natural law’ preferred by our founders, was the most cited legal author between 1790 and 1820. We certainly didn't adopt the laws of England, the legal system we had just rejected. How could we? We are a nation of immigrants who must share the ideas of what freedom is. Our leaders needed fealty to our Constitution which was the doctrine designed to insure protection of those freedoms.
Birth records are a straw dog. Obama is constitutionally ineligible, and is counting on our not being disciplined enough, or smart enough, to enforce our fundamental law.
And he's already won that bet once, just by being elected. He probably figures if he stonewalls the issue long enough, he'll continue to enjoy his winnings.