Cruz need not resort to a statute for US citizenship, does he? If so, it means Congress could, by changing the statute, effectively amend the constitution. A statutory change would redefine the meaning of "natural born citizen" under the constitution.
No. Citizenship at birth is conferred either by location of birth or by blood. His was conferred by blood. The result: he was born a citizen.
Natal = birth
Nat(birth)ural Citizen = citizen at birth
Any legislation in terms of paperwork is based on recognizing what IS. A consular report of birth abroad is no different than any citizen at birth getting a birth certificate.