A Kenyan American, a Cuban American and a Canadian American all tried out for the presidency of the United States. The Kenyan American said, "I'm eligible because the Founding Fathers believed a person with an African dad would make a fine president, would have no divided loyalty, and wouldn't even have to prove he was born here in the U.S. until well after he got into office." He said they put that logic right into the Constitution in Article II.
The Cuban American said, "I'm eligible because both my parents come from a brutal communist dictatorship that aimed nuclear bombs at the United States, but because they escaped in time to have me born in Florida, the Founding Fathers believed I would have no split allegiances of any kind, and I would be a perfect candidate for the presidency and the nuclear launch codes." He dropped out of the race when too few people voted for him in the primaries. Cuban law claims him as a citizen, as they do for everyone with even one Cuban parent, but Americans like to ignore that, because it would make things difficult with such a hostile enemy.
The Canadian American, who is also a Cuban American thanks to his Cuban refugee dad, giving him triple citizenship, said, "I'm a Harvard law grad, and I can tell you for certain the Founders would believe I'm eligible because I renounced my Canadian citizenship last year. I can also tell you it is a 'settled matter of law' that being born in a foreign country like I was doesn't matter, because I have at least one American parent, my mom, and that's how the Founders planned to protect the presidency, right there in Article II. Paternity didn't matter to them, despite what the British thought." The British thought nationality came from your father, not your mother. Other countries thought it was land based, or both.
But then John Jay spoke up. He became our first Chief Justice of the U.S. Supreme Court. Back in 1787 he said we have to prevent any chance that the commander in chief and the presidency "be given to, nor devolve on" foreigners, in a letter to George Washington, and Washington had written back to agree. [I have those letters posted here.] That's why the Committee of Eleven, the group appointed by the Constitutional Convention to do a lot of the editing of the Constitution while it was being drafted, wrote Article II to require only a "natural born Citizen" could hold the office of president and commander in chief of our military forces. They changed Alexander Hamilton's weaker draft.
So modern-day skeptics asked, "How did those old dead white guys even know what a 'natural born Citizen' was, or that it was the correct phrase? They might have used a term like that, in that critical spot, and just guessed at its meaning! They didn't even define it in the document itself!"
To which a frustrated uninvited ombudsman blurted out, "Only brain-dead idiots or followers of network "news" could believe such poppycock! They didn't go defining ANY of the terms in the Constitution. They knew EXACTLY what their words meant. Those white men were inspired geniuses. The definition of that exact term was written down at that time for Pete's sake."
In a reference book Ben Franklin brought to the Convention, Law of Nations, that phrase is precisely described, and it means just what you would expect if the Framers were trying to guarantee a 100% American president free from foreign entanglements, like Jay and Washington discussed in writing.
Law of Nations says, in Section 212: "Natural born citizens, are those born in the country, of parents who are citizens." That's it. A three-part requirement. Two citizen parents at the time of birth (jus sanguinis in Latin, "of the blood"), on U.S. soil (jus soli in Latin, "of the land").
No Kenyan Americans. No Cuban Canadian Americans who renounce foreign citizenship the year before they run for office. Sorry folks, some people are not eligible. That was the Founding Fathers' plan. How foreign is too foreign? Any.
Ben Franklin wrote a long letter back to Charles Dumas in 1775, who provided their copies of Law of Nations by Emer de Vattel (Ben had gotten three), to thank him and tell him, "...the circumstances of a rising state make it necessary frequently to consult the law of nations. Accordingly that copy, which I kept, has been continually in the hands of the members of our Congress, now sitting..." He also mentioned, among many other items, they were working hard to make saltpeter, desperately needed to manufacture gunpowder. The letter is in the National Archives.
The Convention used "natural born Citizen" in only one place and to this day has only one use in our entire body of law -- as a restriction on who can be president and commander in chief. Every other official requirement in law uses the plain word "citizen," a condition that can be achieved in numerous ways, including after birth, and appears constantly in law. Natural born citizenship can only occur at the moment of birth.
A Kenyan American, a Cuban American and a Canadian Cuban American were sitting in a bar, having read this short essay and asked themselves, "So, what do we do now?" The Canadian Cuban American said, "I'm eligible for the U.S. Supreme Court, and since I'm a Harvard law grad, even though that's not a requirement, I think I'll go for that." The Cuban American said, "I'm a U.S. Senator, and even though I rarely vote there and too few people voted for me, I'll try to stay there." And the Kenyan American said, "I may have a problem, I'm going to seek legal advice from an undisclosed location." And everyone lived ever after, for a while.