The founders held that allegiance flowed from parentage, not from place of birth.
By common sense, it has to be recognized that the child is utterly unaware of its place of birth. For a very significant part of his life, his family is all he knows. That is the only thing that is likely to influence allegiance.
What a foreign country may claim or wish is so utterly irrelevant, unless the child is raised there, which is why the return to the home of the parents is important.
-- What a foreign country may claim or wish is so utterly irrelevant, unless the child is raised there, which is why the return to the home of the parents is important. --
I'm positive that I said, earlier, that the concern was the possibility of action, by the foreign nation, when the child (now adult) is in the foreign land, again. As president (head of state), the adult likely has the status of a diplomat, but that status does not attach to a candidate for president, nor does it attach to a president.
Practicalities direct that the effect I am describing is probably inconsequential - no country is going to claim a right to jail or otherwise control a candidate or an ex-president based on soil-birth citizenship. I raise the point just to share, briefly, something I have learned in my studies.