November is soon to come, and this year it brings more than just the carving of the Thanksgiving turkey. That’s because it’s time to select a new commander-in-chief. As nominees Donald Trump and Hillary Clinton face off to replace President Obama, let’s look back on some interesting mathematical events from past elections.
1820: The last unopposed election
In 1820, the sitting president, James Monroe, was the only candidate running. Yet even though he didn’t have an opponent, he failed to win every Electoral College vote! A New Hampshire elector opted to back John Quincy Adams instead, meaning that Monroe won the election with 231 of 232 Electoral College votes.
1876: The closest election
In perhaps the most contested election in US history, Rutherford B. Hayes defeated Samuel J. Tilden by a single electoral vote! That’s the closest in US history. (It’s hard to get any closer!) To complicate things further, Tilden won the popular vote by over two hundred thousand votes—one of four times in history someone won the popular vote but lost the presidency. On top of that, the 1876 election was marred by fraud and violence, and Congress had to create the Electoral Commission to decide the president. In the end, Hayes only took the office after a number of additional political battles.
1948: Polling gone wrong
The Chicago Tribune, relying on many early polls, predicted that Thomas E. Dewey was going to defeat incumbent president Harry S. Truman, so they chose “Dewey defeats Truman” for their first edition headline on the day after the election. As it turns out, votes from the east coast hadn’t been counted when the Tribune went to press, and Truman pulled off one of the biggest upsets in American election history. He ended up winning with 303 electoral votes to Dewey’s 189, and was famously photographed holding the paper that announced his defeat.
1960: The closest popular vote
John F. Kennedy and Richard Nixon squared off in the presidential election of 1960. In the shadow of former president Dwight Eisenhower, the candidates were nearly evenly matched: Kennedy received 49.72 percent of the vote while Nixon received 49.55 percent. The difference between them was only 112,827 votes—that’s even smaller than the city of Waco, Texas!
2000: The Florida Recount
The 2000 election is perhaps the most controversial in recent history. The contest was between George W. Bush and Al Gore, and it the winner was going to be decided by who won Florida. On Election Day, there was mass confusion and controversy, with news organizations claiming Gore won, then Bush, then saying it was simply too close to call. When they finally counted all the votes, Bush had won by 1,784. But a margin that small required a recount, according to Florida law. That process led to a number of legal issues that weren’t solved for over a month. In the end, Bush won Florida by a margin of 537 votes, and with it won the presidency by a mere five electoral votes.
2016: Polls gone wrong again
This year’s election has had notable moments as well. In particular, predictions about the Michigan Democratic primary earlier this year were “among the worst polling errors in primary history,” according to statistician Nate Silver. According to polls, Hillary Clinton was leading Bernie Sanders by 21 percentage points had a 99 percent chance to win—yet Sanders eventually took the state by 1.5 percentage points.