There was that British bloke Edward-something who married an American woman. Simpson I think her name was. Whether or not Edward remained King of England with Simpson as his queen or merely the duke and dutchess of Windsor, the Cruz supporters would insist that their royal offspring were natural born US citizens eligible for the US presidency. In fact, said offspring would have precisely the same quality of citizenship as Mr.Cruz. ex-pat mother marrying a foreigner in a foreign land.
Cruz supporters will tell you that is exactly who Founders John Jay and George Washington had in mind for the president when they constructed the eligibility clause of the Constitution.
What if china passes a law saying trump is Royal Chinese blood citizen? Does that make him no longer NBC?