Cruz could show US his paperwork... Then we would know when or if he has US citizenship. He would have paperwork. The responsibility is his. Ted Cruz’s parents did not give him ‘natural born’ US citizenship, and only they could give him ‘natural born’ US citizenship.
The only “paperwork” Cruz (or George Romney, or John McCain), etc., have is their birth certificate. An American citizen born abroad is not naturalized, therefore they would not have additional paperwork that a naturalized citizen would have.
Naturalization is a separate and affirmative action. Simply being born as an American citizen is sufficient in his and these other cases.
I have to go back to work now and can’t Freep any more tonight. Have a good one.
As a closing thought, here’s an interesting look at the issue from Richard Primus of the University of Michigan Law School:
http://www.politico.com/magazine/story/2016/02/ted-cruz-citizenship-fight-president-2016-213660
Have a good night.