From the Dept. of Oops: In a release promoting a proposal on term limits  for Boston mayors, the Yoon camp goofed on the number of popes and U.S. presidents since 1968.
Noting that there have been three mayors (Kevin White, Ray Flynn, and current incumbent Thomas Menino) since then, the campaign said there had been 10 U.S. presidents and five popes.
In actuality, there have been 9 U.S. presidents (Lyndon Johnson, Richard Nixon, Gerald Ford, Jimmy Carter, Ronald Reagan, George H. W. Bush, Bill Clinton, George W. Bush, Barack Obama) and four popes (Paul VI, John Paul I, John Paul II, Benedict XVI).
Or maybe they were counting the Pope from "Family Guy" .
In any case, it wouldn't be the first campaign trail goof  among the candidates. (Menino declared that the curriculum in Charlestown doesn't include the Battle of Bunker Hill. It does.)
The Lit Drop stands by its suggestion that when the debates are scheduled, that maybe they include a history portion .