Yes, it is cut and dried - one more time:
My grandson was born in London to my son who is an American citizen and to his mother, a British citizen. On the day of his birth, he was recorded as a British citizen AND an American citizen and was issued an American passport on that day of his birth.
When a child is born in a hospital, parents fill out a form declaring him a citizen and the hospital sends that form to the government - the hospital itself cannot make a baby a citizen of any country. On the day of my grandson's birth, two forms were sent, one to the British government making him a British citizen AND, at the American Embassy, one sent to the American government making him an American citizen.
Cruz was made an American citizen exactly as my grandson was made an American citizen.
When grandson arrives to this country by plane, he goes to the American citizen line to enter the country. If his mom comes, she has to go to the non-citizen line to enter the country.
Well, your grandson happened to meet the conditions, as the American Embassy confirmed. But not all children born out of the country, of parents with mixed citizenship, meet the statutory conditions for conferring citizenship on the child.
I wasn't making any contention as to whether or not Cruz's parents met the statutory conditions, I was merely criticizing the author's over-broad contention, that ALL children born of one US citizen parent are ALWAYS US citizens.