It's only a "living document" when that benefits the Dems.
If there was any plausible way to label Cruz as ineligible due to his Canadian birth with a non-citizen parent, you can be totally sure that the Dems will have an October Surprise lawsuit lined up.
I'd bet on it. Their justification will be that bammie was born in Hawaii so it's not the same thing.
Two citizen parents with a child born on the soil renders this a moot point, anything else there is doubt.
The Founding Fathers did not want doubt or question.