Once you amend the Constitution, its original language must be read in the context of the amendment, its no longer the original document. I believe that this was what the founders intended.
All you have to do is look at the SCOTUS case of 1952 Kawikita v. United States that says otherwise. Mario Appuzo has added that case to his appeal to the US Supreme Court.
I do think that you are right in respect to American Indians who proclaimed primary allegiance to their respective tribes. Certainly, the author of the citizenship clause made that argument and was supported by several other senators and was later upheld by the Supreme Court. That argument no longer holds, any American Indian born in this country is a citizen by birth.
Interestingly, the argument against granting citizenship to American Indians under the 14th Amendment, acknowledged that all others excepting children of diplomats were citizens by virtue of their birth.
Before we had Free Republic, we only had the courts to decide such matters.