If you have to point to a positive (man-made) law or man-made regulation then that nullifies the ‘natural’ part of ‘natural born Citizen’ it would seem.
Puerto Ricans are actually US citizens ‘at birth’. But they are naturalized ‘at birth’ under collective naturalization. Since naturalized citizens are not natural born citizens it is obvious that just being a citizen AT birth is no a criteria for meeting Article II, Section 1 requirements.
Even some websites that specialize in visas and citizenship issues indicate that to be a citizen AT birth BOTH your parents must be US citizens.
See here:
http://www.visalawyergroup.com/frequently-asked-questions/naturalization
From above link:
“2. Who is born a United States citizen?
Generally, people are born U.S. citizens if they are born in the United States or if they are born to U.S. citizens:
By being born in the United States
If you were born in the United States (including, in most cases, Puerto Rico, Guam, and the U.S. Virgin Islands), you are an American citizen at birth (unless you were born to a foreign diplomat). Your birth certificate is proof of your citizenship.
Through birth abroad to TWO United States citizens
In most cases, you are a U.S. citizen if ALL of the following are true:
Both your parents were U.S. citizens when you were born; and
At least one of your parents lived in the United States at some point in their life.”
Notice the strong requirement that BOTH parents must be US citizens.
Such is not the case for Mr. Cruz.
So lets break this down into specific quesitions:
Do you agree that someone who is a US citizen at birth is not naturalized but in fact, was naturally born a US Citizen?
Do you agree that someone born on US soil/jurisdiction is a US Citizen at birth?
Do you agree that US Citizenship at birth can be obtained even if born outside the boundaries of the United States?