Birthright citizenship is conferred by virtually every country in the Americas so the definition logically applies to Cruz vis a vis Canada. I don’t see the big deal except his parents clearly did not give birth in Canada for the purpose of conferring dual citizenship.
The term "anchor baby" does not apply to "every country in the Americas." It is an American term.
As to the legitimacy of birthright citizenship, consider this. Unless you are a fan of bonded indenture, I'd suggest the term and policy should concern you.