No doubt liars have served in public office ever since the first candidate printed a handbill and later evolved to taping a radio or TV commercial or clicking on social media. It’s as American as apple pie, and as dishonest as the pie stuffed with applesauce instead of apples.

And if the candidates themselves were too honest to tell a fib, their campaign managers or biographers would step in and put out a lie to make the candidate look better. Even the story about how George Washington, our nation’s first president, had fessed up to cutting down a cherry tree as a youth was made up. One...