[Professor Philip Tetlock of the University of California, Berkeley] studied pundits and discovered they were, to a rough approximation, always wrong when making predictions. He took 284 pundits and asked them questions about the future. Their performance was worse than chance. With three possible answers, they were right less than 33 per cent of the time. A monkey chucking darts would have done better. This is consoling. More consoling still is Tetlock's further finding that the more certain a pundit was, the more likely he was to be wrong. Their problem being that they couldn't self-correct, presumably because they'd invested so much of their personality and self-esteem in a specific view.
Pundits often have experience or inside knowledge that can improve our understanding of national politics. David Gergen, a CNN mainstay, has served in four presidential administrations. His commentary should leaven the public debate. But maybe he should limit himself to telling us (1) how current political events conform to or differ from past ones and (2) what his sources in power are saying. Because it doesn't appear Gergen and his pals are any better at predicting the future than you or me.