We’ll begin with what went wrong with the Republican debate in Boulder, Colo., then look at what went wrong with Jeb Bush.

CNBC’s debate moderators have famously come under fire for questions, statements and a tone that were obnoxious. They were. The moderators seemed intent on trivializing the field. When you say, “Candidate A, you have criticized Candidates B and C, turn to them now and tell them why they’re dopes,” you are presenting yourself as the puppet master and them as puppets. They must either attack their colleagues...