“...if it is factual that Cruz’s mother did indeed take Canadian citizenship prior to Ted’s birth”
Cruz’s mother moved to Canada in 1967. Ted was born in 1970. At that time, one needed to be residing in Canada for five years before getting (or maybe it was applying for) Canadian citizenship. There may be other reasons for Cruz not to be a NBC, but his mom was an American citizen at the time of his birth.
That clears up my question. Thank you.