If his mother became a Canadian citizen and repatrioted, is Cruz still natural-born?
The list was a census list, listing all the people, not an official voter list. His mother did not become a citizen of Canada - even if she wanted to, she had not lived there five years which is required to become a citizen - she was there 3 years only. She did not give up her US citizenship.
One would have to be a nut case to give up US citizenship and she was a graduate of Rice University in Houston, the same University my son attended and graduated. They only accept 500 new students every year, and those have to be extremely smart or they do not get in. Due to his scores and community service (working for free for NASA in the summers), my son was accepted to Rice and automatically became a member of MENSA. I tell you that background to underscore the fact his mother had to be highly intelligent to attend Rice. No smart person would ever give up US citizenship.