Yes it is.
"One can only naturally be born a US citizen when there is no alternative to being anything else, born here of citizen parents."
No that's wrong. That is not what it means. A natural born citizen is one that is a citizen by birth, as opposed to a citizen that is naturalized. Being born within the country makes you a citizen by birth, a natural born citizen.
Natural born is not the same in all cases as a citizen born in the country.
The 14th Amendment is very clear on this.
You have non citizen parents, you are under the jurisdiction of their country, even if you are born on the White House steps.
Vattel says both parents have to be citizens, and their offspring is a natural born citizen. There were at two copies of Vattel(1758) at the Constitutional Convention in 1787 (via Franklin and Washington).
Obama,Cruz,Haley,Jindal—not eligible to be President.
Eight years of Obama taught us to take the Constitution literally.
And the King of Thailand was eligible too..........
he was born in Cambridge MA