Vattel is used in context like a legal dictionary that the framers used so we can understand the terms they used in the legal context they viewed them from. There may be terms we use now that had a different context or meaning when the framer's wrote the Constitution. It isn't an end, but it is a means to an end, it gives the NBC argument (re two citizen parents) a legal base to start from.
In context of who can be eligible to be president, there's nothing else to look at. Nothing newer has been enacted or modified. The most significant and relevant modification to citizenship law since the framing of the Constitution would be the 14th amendment, yet even after it was ratified, the Supreme Court still noted on two occasions that the definition of natural born citizen could only be found outside of the Constitution ... as in NOT within the 14th amendment.
Except the phrase “Natural Born Citizen” didn’t appear in any translation of Vattel until 10 years AFTER the Constitution was written, and it is a poor translation of what he wrote, which was - if one just transliterates - ‘the natives, or indigenous’.
Pretty hard for the Founders to use Vattel as a legal dictionary for NBC when Vattel didn’t HAVE NBC until AFTER the Constitution. Had they relied on Vattel for their legal term, they would have required the President be a “native citizen”...
But not a legal base grounded in U.S. law.
Vattel is not a legal dictionary. Context, sure.
"It isn't an end, but it is a means to an end, it gives the NBC argument (re two citizen parents) a legal base to start from."
But in fact Vattel doesn't provide that definition. Birthers get this wrong, like so much else. Vattel never used the term. And the passage birthers quote wasn't a definition Vattel was imposing, it was an observation about what various countries already did. But England wasn't one of those countries, as Vattel himself noted.