For many years, journalists have analysed public figures through a simple, cynical lens: Why is this lying bastard lying to me? But maybe we also need to ask the opposite: Why are they telling us the truth?

Exhibit one: Kristi Noem, governor of South Dakota. She had been mentioned as a possible vice-presidential candidate for Donald Trump. So, as American politicians insist on doing, she is publishing an autobiography. Unfortunately for her, the book has already proved a little too honest.