The race is close! Talking heads and voters chatter nervously about the prospect that the election contest will be settled in court. An Electoral College tie could yield a Republican president and a Democratic vice president. It’s tempting to think that this is just the American way: the fate of the country resting on a few battlegrounds. But today’s partisan strongholds were yesterday’s swing states, and winners have sometimes won handily. Below, Slate challenges you to demonstrate your grasp of presidential election history.