“If I understand your point here, it’s that the 14th amendment worked a change to the definition of natural born citizen as expressed in the constitution.”
That is the nub of the issue wrt the eligibility arguments.
Did the 14th amendment change things?
If the 14th amendment changed the conditions for citizenship at birth, and it did, and if ‘natural-born citizen’ is just a term of art referring to those who acquire citizenship at birth, then it follows that those born as US citizens under the 14th amendment birthright citizenship clause are indeed ‘natural-born citizens’.
That line of reasoning is the reasoning the SCOTUS would likely hold, since it lines up with the reasoning in Wong Kim Ark.
OTOH, it never has been specifically and explicitly held, so it gives some space for various theories.
But Wong Kim Ark itself worked a change in the way the government saw and applied the 14th amendment. It worked a radical narrowing of "subject to the jurisdiction," and while arguable, it's basically an immigration policy decision for most purposes.
The Wong Kim Ark decision was not "Wong Kim Ark is a natural born citizen, entitled to all rights of natural born citizenship (including eligibility to be president)." It said he was every much a citizen as a natural born citizen. So is every naturalized citizen every much a citizen as a natural born citizen.
Why didn't the Wong Kim Ark court say, directly, that Wong Kim Ark was a natural born citizen? Why is his citizenship "every much," and not "it?"
I agree that for all people, except those who hold the office of Pres and VP, the line of reasoning holds up fine. But not for Pres and VP.
I was reading a bit this morning, and learned that there is a cottage industry for Koreans and Japanese mothers to come to the US to give birth, after which they return, with child, to their country. These citizens of the US will be raised in a foreign land, and the birthright citizenship is used to open the possibility of education in the US, and similar perceived advantages. Is that what the founders intended, by qualifying only the Pres and VP as needing to be natural born citizens?