“but I have not bothered to find it.”
You will have to try a little harder then that - hand waving is not a legal argument.
It allows split citizenship because if an American women married a foreign national, she doesn’t lose her citizenship like the 1907 bill required. Nothing you have posted challenges this.
It's what your side has been using from the beginning, so I am surprised to see you objecting to it now. :)
Your argument is Any person born here is a "natural born citizen" just because. (English Law says so or something.)
It allows split citizenship because if an American women married a foreign national, she doesn’t lose her citizenship like the 1907 bill required. Nothing you have posted challenges this.
Mackenzie v Hare, posted previously. Prior to that, it was a mixed bag. Sometimes they did, sometimes they didn't. In any case, it was an unusual circumstance.