The SCOTUS uses Vattel when it needs to know what the Founding Fathers rationale was for certain phrases, such as “to keep and bear arms”: Sure. But that's not a citation as a legal precedent but rather for the purpose of defining what the intent was.
I'm not in any way critical of Law of Nations or of using it as secondary authority.
But it's a mistake to look at it as overriding legal authority of greater significant than the common law or the historical legal authorities. Cause it isn't.
On the narrow issue here ("natural born"); Law of Nations and the letters exchanged among Madison and Jefferson and Hancock are a pretty good indication that the founder's obtained and used the term by adapting the legal concept of "natural born subject" from English Common Law. I think you then ought to look at the underlying Common Law to find out what the legal rules are that would determine whether or not a given individual is or is not a "natural born".
Although I also think that on the Obama facts, there is a pretty good legal argument that he ought to flunk even if he was born in Hawaii--I doubt the Supreme Court would come down that way if the issue were presented.
I think the way you get the legal system involved to determine that he is not President is likely to require that you prove or at least make a prima facia showing that he was not born in the US. Although I will also concede that to a large extent, my view is somewhat affected by the fact that I see the evidence, secondary though it is, as pretty conclusive that he was born in Mombasa which is located in modern day Kenya.
