First off, it is not circular, second, it is the same section of the law (subsection A) that states if you are born in the US, you are a citizen. Mr Cruz acquired his US Citizenship by his US Citizen Mother at birth therefore he has never needed to be naturalized.
Now I have cited specific sections of the Constitution, historical facts, and the laws of this land. It is now time for you to start citing one of those three to support your opinion.
Your “rationale” is entirely circular.
Pub. L. 82-414 § 301(a)(7), Pub. L. 82-414 § 301(b)
Cruz is defined in law, “citizen”.