Republican candidate Barry Goldwater was well-known for his hardline small government anti-communist rhetoric, and in his acceptance speech for the 1964 GOP presidential nomination defended his "extremism."
His campaign team attempted to appeal to the gut instincts of American voters with the slogan: "In your heart, you know he's right."
But the response of his Democrat opponent, Lyndon Baines Johnson, was devastating.
"In your guts, you know he's nuts," ran the Democratic reply in campaign ads and posters.
Johnson won by a landslide, taking 61% of the popular vote to Goldwater's 38%. Goldwater won in just six states.