The few people who remember the figure of President Andrew Johnson these days recall two things about him: He was the president who got the job when President Abraham Lincoln was murdered, and he was the first president to be impeached. Neither look particularly good on a presidential resume.

Yet, every time a president faces hearing the dreaded words, “You’re fired,” from Congress, poor Johnson is trotted out of obscurity, and we’re reminded he was the first chief executive to undergo the humiliating experience. It’s the kind of factoid news readers love dropping to show off their knowledge.