It wasn’t quite a campaign promise, but Michael Dukakis’s answer to a question about his stance on the death penalty in a 1988 debate is widely seen as costing him the election. Damn it was a hell of a question, though.
In a debate against Vice President George H.W. Bush, moderator Bernard Shaw dropped this bombshell: “Governor, if [your wife] Kitty Dukakis were raped and murdered, would you favor an irrevocable death penalty for the killer?" Dukakis was supposed to express his sympathy with the victims of crimes, political operative Susan Estrich wrote later. But he didn’t.
Rather, he stayed on message "No, I don't, and I think you know that I've opposed the death penalty during all of my life." Wrong answer, but whatever. What’s crazy is to have a presidential candidate talking about his wife’s imagined rape and murder on national television.