Where the heck did you get that nonsense? You're the one who brought up the age of the child. Which is irrelevant. Ignorance of the law is no excuse for child or adult.
“Where the heck did you get that nonsense? You’re the one who brought up the age of the child. Which is irrelevant. Ignorance of the law is no excuse for child or adult.”
Nonsense? When Heinlein advocated the very thing? A limited model of citizenship isn’t something new, it goes back to the Roman Empire.
One of the problems that arises is slavery. If you set something like this up, there is a market for non-citizen labour as there are fewer legal restrictions. Which is why the 14th explicitly says that it applies to everyone born in the United States.