I spent about 20 years getting people ready to answer questions from tough and even hostile inquisitors. It is what trial lawyers do. I can thus attest that over-preparing a witness can be worse than failing to prepare the witness at all. Ironically, this is especially so with a smart witness.
A person of merely average intelligence is apt to follow advice. A seasoned lawyer can quickly demonstrate how foolish he can be made to look if he doesn’t listen carefully to the questions, or if he readily accepts a loaded question’s premise. The smart guy who radiates self-confidence is often a different story. He outsmarts himself. He thinks, “What would I ask me?” Worse, he manages to hear the question that he calculates should be asked, which is not always the question that is actually asked. When he is over-prepared — when he and his handlers have pored over his vulnerabilities and meticulously scripted what he will say when grilled about them — the smart guy will give the scripted answer. It can end up sounding dumb, even smarmy, if he has the question wrong.
I think that’s what happened to Jeb Bush when he was asked about Iraq by Fox News’s Megyn Kelly this week.