Except the law of the land states:
8 U.S.C. § 1401
“The following shall be nationals and citizens of the United States at birth:
(g) a person born outside the geographical limits of the United States and its outlying possessions of parents one of whom is an alien, and the other a citizen of the United States who, prior to the birth of such person, was physically present in the United States or its outlying possessions for a period or periods totaling not less than five years, at least two of which were after attaining the age of fourteen years...”
https://www.law.cornell.edu/uscode/text/8/1401
That is why no judicial ruling or act of Congress has found Ted Cruz to be ineligible.
That law states “citizen”. Nowhere does it state “natural born citizen”.
“citizen at birth = natural born citizen” is a myth.