Hello. They are digging into his American mother’s background to see if she became a Canadian. She never lived there long enough nor did she ever attempt to become a Canadian. If she were a Canadian, it would most likely disqualify Ted Cruz as not a natural born citizen.
No, it wouldn't - as long as she still held her U.S. citizenship at the time of his birth. Canada law allows for dual citizenship. But this is moot as she was not a Canadian citizen at the time of his birth, period.