Zivotofsky v. Kerry is a citizenship case over someone born in Jerusalem to US Citizen parents. His mother wants the place of birth listed on her son’s passport to be “Israel.” The United States does not recognize the sovereignty of Israel over the city of Jerusalem and refused the request. That’s the controversy.
Justice Clarence Thomas in a concurring opinion implied something interesting, something that I have said myself in other words:
… In order to establish a “uniform Rule of Naturalization,” Congress must be able to identify the categories of persons who are eligible for naturalization, along with the rules for that process. Congress thus has always regulated the “acquisition of citizenship by being born abroad of American parents . . . in the exercise of the power conferred by the Constitution to establish a uniform rule of naturalization.” United States v. Wong Kim Ark, 169 U. S. 649, 688 (1898) ; see also Miller v. Albright, 523 U. S. 420, 456 (1998) (Scalia, J., concurring in judgment) (recognizing that “Congress has the power to set the requirements for acquisition of citizenship by persons not born within the territory of the United States”). It has determined that children born abroad to U. S. parents, subject to some exceptions, are natural-born citizens who do not need to go through the naturalization process. 8 U. S. C. §§ 1401(c), (d), (g).
My reading of Justice Thomas’ opinion suggests that in his mind natural born citizen means citizen at birth. I say that because the statute cited is headed: “The following shall be nationals and citizens of the United States at birth.”
Of course this is not the majority opinion and sets no precedent, but it does give us a hint as to how Justice Thomas would vote, should a Cruz eligibility case come before the court.