And Congress has made equally clear from the time of the framing of the Constitution to the current day that, subject to certain residency requirements on the parents, someone born to a U.S. citizen parent generally becomes a U.S. citizen without regard to whether the birth takes place in Canada, the Canal Zone, or the continental United States.
If the touchstone is "citizen-at-birth," these authors have overlooked the statutes that confer US citizenship at birth, regardless of the citizenship of the parents, to persons born in Guam, Puerto Rico, and the Virgin Islands.
Would those persons "naturally" be citizens without an Act of Congress?
Would Cruz be a citizen without an Act of Congress?
Not to say that "Act of Congress" is the touchstone for NBC. Rather, "citizenship that depends on Act of Congress" is the touchstone for naturalization. At least "so says SCOTUS and all the other courts."
Would any of us be?