Come to think of it, what would be the harm in Cruz waiting four years and getting this settled? He's confident it will be settled in his favor, so get it done in the four years, beyond any legal possibility of challenge. I don't know why Cruz hadn't done that earlier.
It's ironic that this chore should be easy. It's been made difficult due to the presence of statutory citizenship that grants citizenship at birth, the passage of time, etc.
But imagine if you will, there aren't any citizenship laws other than natural law, what citizenship one would more or less "naturally" assign to a person.
I'm not saying that how the decision will be made by the deciders, just saying that's a better mind set than rhetorical gymnastics and relying on statutes.