The Supreme Court of the United States has never applied the term “natural born citizen” to any other category than “those born in the country of parents who are citizens thereof”.
"The citizenship of no man could be previous to the declaration of independence, and, as a natural right, belongs to none but those who have been born of citizens since the 4th of July, 1776."....David Ramsay, 1789.
A Dissertation on Manner of Acquiring Character & Privileges of Citizen of U.S.-by David Ramsay-1789
The Law of Nations or the Principles of Natural Law (1758)
The Laws of Nature and of Nature's God: The True Foundation of American Law
Yet, I didn't see a single Supreme Court case cited in support of your contention. Nor a single scrap of correspondence between the Founding Fathers describing precisely what they meant by the phrase. Nothing that would, in any way, disqualify Ted Cruz' candidacy.
Instead, you are basing the contention on your opinion...and the opinion of others who are irrelevant to the discussion An opinion that, oddly, nobody (with any expertise or authority) was prepared to voice when Obama announced his intention to seek the Presidency. Yet, the fact that Obama's father was not a U.S. citizen was near-universal knowledge.
The fact is that we don't exactly know what was meant by the phrase -- beyond what it was traditionally assumed to mean. And to presume that the Founding Fathers would not have been bound to respect the Congress' subsequent definition of citizenship is, well, presumptuous.
Personally, I remain convinced that this "natural born" issue was introduced into the eligibility controversy by Obama's own people as a red herring, to distract from the birth certificate issue. It's a wild goose chase.