The premise is false and correct at the same time? I think I see your problem here.
but that if a “manmade” law confirms that natural right or principle then suddenly it is only through operation of a “manmade” law - and no longer a natural right or natural law principle.
That is ridiculous and idiotic.
Yes it is, but that's because you are misstating it. I believe this is called the "Straw Man Fallacy."
The man made laws are not confirming a natural right. They are creating a positive law that grants the same privileges as a "natural right." Once more, this is called "naturalization."
The Principle is exactly like that of Adoption. A Child who is not part of a family is adopted, and thereafter can claim the benefits of being part of that family, including the characteristic of name.
Birth to family = Natural born.
Adoption = Naturalized.
Adoption at birth = Naturalized.
Born in Family House = squatter.
Tell me you understand the difference between a natural born child and an adopted child.
.
Now apply the idea to citizenship.
Why are the “manmade” laws confirming a natural law in one case but only creating “manmade” law in another? Based upon what YOU deem to be the operation of natural law and natural principles?
I say the operation of “manmade” law confirms the natural allegiance at birth due to natural law principles of place and/or parentage.
You say the operation of “manmade” law confirms natural law in some cases, and is only “naturalizing” in others.
If parentage is the criteria you prefer - why your opposition to Cruz who gets his citizenship at birth through the natural law principle of parentage?