My opinion is based on the work by Horace Binney who addressed this very topic in 1853 and came to the ultimate conclusion that you are, with few exceptions, a Natural Born Citizen of the country where you were born. Binney graduated from Harvard in 1797, studied law under Jared Ingersoll who had been a member of the Constitutional convention, was an attorney in Philadelphia for half a century, the attorney general of Pennsylvania twice, a Whig in the House of Representatives from 1833-1835, and actually defended Abraham Lincoln's suspension of habeas corpus during the civil war.
What's more, this specific work has shown up in many past supreme court cases pertaining to citizenship as supporting evidence for the final and dissenting opinions. For example, Ginsburg used it in Miller v. Albright in 1997 when she disagreed with the courts opinion there.
His opinion is, in other words, worthy of our consideration.
This is a fairly complex topic and, simple answers are not easily discerned and, as such, opinions are frequently offered up as matters of fact. One has to be willing to research material that is far beyond the normal scope of a normal internet disagreement to find the truth of the matter and I have done that. I will cut and paste from Binney's work and you may read it if you like or not. If you prefer, you may direct yourself to the boldfaced type where I have highlighted some very clear specific references pertaining to our disagreement.
Here's what Binney said, and yes, I am selectively editing his work simply to make my point more easily discernable:
THE ALIENIGENE OF THE UNITED STATES
By Horace Binney"
Every subject is either natus born, or datus given or made. 7 Rep. 17 a.
There be regularly, unless it be in special cases, three incidents to a subject born. 1st, That the parents be under the actual obedience of the King. 2nd, That the place of his birth be within the King's dominion. And, 3rd, The time of his birth is chiefly to be considered, for he cannot be a subject born of one kingdom, that was born under the allegiance of another kingdom, albeit afterwards one kingdom descend to the king of the other. 7 Rep. 18 a.
"The being born under the allegiance of another king, is the touchstone to try whether alien or not." Jenkin's Cent. P. 3, Cent. 1, case 2.
.........
The doctrine, that a person born out of the dominions of the King of England, and under the actual obedience of a foreign king, is by the common law, an alien, though his parents were English, may be found in all the abridgments. See 1 Bac. Abr. 193, Alien; 1 Com. Dig. 552, Alien; for, "being born out of the King’s ligeance," has this meaning by common law.
Blackstone says that the common law stood absolutely so, with only a very few exceptions, 1 Black. Comm. 372; and these exceptions, perhaps, are confined to the cases of the children born abroad, of ambassadors and their wives, natives of England, Calvin’s case, 5 Rep. 18 a; persons who are born within the places possessed by the Kings army, if he enters the territories of another prince in a hostile manner, and the parents are subjects and not hostile, Craw vs. Ramsay, Vaugh. 281; and persons born subject to a prince, holding his kingdom as homager and liegeman to the King of England, during the time of his being homager, Calvin's case, 7 Rep. 21 b.
The state of the law in the United States is easily deduced. The notion that there is any common law principle to naturalize the children born in foreign countries, of native-born American father and mother, father or mother, must be discarded.
But the common law principle of allegiance, was the law of all the states at the time of the Revolution, and at the adoption of the Constitution; and by that principle the citizens of the United States are, with the exceptions before mentioned, such only as are either born or made so, born within the limits and under the jurisdiction of the United States, or naturalized by the authority of law, either in one of the States before the Constitution, or since that time, by virtue of an Act of the Congress of the United States
As a practical matter, everyone born to an American parent or parents is considered an American citizen, and has been since we have been alive. Our nation is being torn asunder, And IMO the concern about this comes, with few exceptions, from enemies of Cruz.