Often overlooked is the fact that intelligence doesn't grant knowledge or achievement, it only enhances one's ability. When a gifted person uses that ability guided by unethical moral standards, the superego's criticisms, prohibitions, and inhibitions which form the person's conscience are rendered impaired or dyfunctional, resulting in aberrant or deviant behavior. I believe that accounts for both Cruz and Trump. But that's just my opinion.
I have often said that knowledge trumps I.Q., no pun intended.