[P]arents not owing allegiance to any foreign sovereignty here is in the context of who can vote and falls short of "parents who are United States citizens", leaving open the question about Marco Rubio, who is native born and whose parents became citizens a few years after his birth.
I see a very strong argument for Rubio being an NBC. But if one parent, and more so the father, is a foreigner it is clear what that child is not.
Rubio’s parents were in the US with permisson of the US govt, therefore this clause would make Rubio, and Jindal likewise given the same with his parents, naturally born.