“Vitter notwithstanding, the 21st century interpretation of natural born citizen, as evidenced by Barack Obama, is pretty straightforward. Were you born in America?”
No, remember John McCain was born in Panama. There’s now a reasonable consensus among legal scholars that the natural-born citizens are exactly those who obtained their citizenship upon birth.
In U.S. v. Wong Kim Ark the Supreme Court explained that the language of the Constitution comes from English Common Law, and they quoted British jurist A.V. Dicey: “’Natural-born British subject’ means a British subject who has become a British subject at the moment of his birth.’”
Yeah, of course, the WKA court is more in the "know" than two men who were actually there:
October 18, 1787 - James Madison wrote to George Washington, N. York:
"Since the Revolution every State has made great inroads & with great propriety in many instances on this monarchical code.[Edit: Englands "Common Law"] The "revisal of the laws" by a Committe of wch. Col. Mason [Edit: George Mason] was a member, though not an acting one, abounds with such innovations. The abolition of the right of primogeniture, which I am sure Col. Mason does not disapprove, falls under this head.. What could the Convention have done? If they had in general terms declared the Common law to be in force, they would have broken in upon the legal Code of every State in the most material points: they wd. have done more, they would have brought over from G.B. a thousand heterogeneous & anti-republican doctrines, and even the ecclesiastical Hierarchy itself, for that is a part of the Common law."
June 18, 1788 - George Mason, In Convention, Richmond (Debates in the Several State Conventions on the Adoption of the Federal Constitution), states:
"We have it in our power to secure our liberties and happiness on the most unshaken, firm, and permanent basis. We can establish what government we please. But by that paper we are consolidating the United States into one great government, and trusting to constructive security. You will find no such thing in the English government. The common law of England is not the common law of these states."
When the Decleration of Independence and the Constitution were writen, English subjects could not renounce their alligience to the one soverign, the crown:
"Natural allegiance is such as is due from all men born within the king's dominions immediately upon their birth. For, immediately upon their birth, they are under the king's protection; at a time too, when (during their infancy) they are incapable of protecting themselves. Natural allegiance is therefore a debt of gratitude; which cannot be forfeited, cancelled, or altered, by any change of time, place, or circumstance, nor by any thing but the united concurrence of the legislature. An Englishman who removes to France, or to China, owes the same allegiance to the king of England there as at home, and twenty years hence as well as now. For it is a principle of universal law, that the natural-born subject of one prince cannot by any act of his own, no, not by swearing allegiance to another, put off or discharge his natural allegiance to the former: for this natural allegiance was intrinsic, and primitive, and antecedent to the other; and cannot be devested without the concurrent act of that prince to whom it was first due. Indeed the natural-born subject of one prince, to whom he owes allegiance, may be entangled by subjecting himself absolutely to another; but it is his own act that brings him into these straits and difficulties, of owing service to two masters; and it is unreasonable that, by such voluntary act of his own, he should be able at pleasure to unloose those bands, by which he is connected to his natural prince."William Blackstone, Commentaries 1:354, 357--58, 361--62
How, then, did they declare their Independence from the King if they were not permitted to do so under English Common law?
They used the principles found in natural law. Vattel states, in the Law of Nations (which is based on natural law), that citizens may renounce (or quit) their citizenship and allegiance to a country:
"Chapter XIX: Of Our Native Country And Several Things That Relate To ItThe founders could never have written our founding document, the Declaration of Independence, had they stuck with or adhered to, English Common law.
§ 220. Whether a person may quit his country.... 1. The children are bound by natural ties to the society in which they were born; they are under an obligation to show themselves grateful for the protection it has afforded to their fathers … They ought, therefore, to love it, as we have already shown, to express a just gratitude to it, and requite its services as far as possible, by serving it in turn … But every man is born free; and the son of a citizen … may examine whether it be convenient for him to join the society for which he was destined by his birth. If he does not find it advantageous to remain in it, he is at liberty to quit it ..."
July 4, 1776 was the beginning of their breaking away from the Monarchical code.