On Jan. 3, 1964, Barry Goldwater, a conservative  U.S. Senator from Arizona, announced his candidacy for the presidency against incumbent Democrat Lyndon B. Johnson. Six months later, he won the Republican nomination. In his acceptance speech Goldwater proclaimed, "Extremism in the defense of liberty is no vice. And let me remind you, also, that moderation in the pursuit of justice is no virtue."

Though his statement rallied staunch supporters, it rattled many politicians -- Republicans and Democrats alike -- who feared that Goldwater's reactionary views would alienate Americans and handicap social progress. Goldwater had a track record of opposing civil rights reform and social welfare programs. Most worrisome to Goldwater dissenters was the candidate's casual openness toward nuclear arms use.

After Goldwater won the nomination, many Republicans distanced themselves from their party's candidate, including New York Governor Nelson Rockefeller, who called Goldwater's extremism "dangerous, irresponsible and frightening." Johnson capitalized on that extremism in his own ad campaigns: Riffing off Goldwater's campaign slogan, "In your heart, you know he's right," Johnson's camp responded, "In your guts, you know he's nuts." Another Johnson slogan, "In your heart, you know he might," referenced Goldwater's stance on nuclear armament.

One particular Johnson television spot, called the "Daisy Ad," showed a young girl picking petals off a daisy and counting to 10. As a low voice cuts in and begins a backwards countdown, the scene morphs into a shot of a nuclear explosion. Though the ad did not mention Goldwater by name, its implication provoked criticism from both parties. The ad aired once on Sep. 7, 1964 and was subsequently pulled.

Throughout the campaign, Goldwater trailed Johnson in the polls, and on election day he suffered a crushing defeat. He carried a mere six states -- most of them in the Deep South -- and won only 38% of the popular vote. The 1964 election became one of the biggest landslides in history, and 20 of the 57 Republican Congressmen who supported Goldwater lost their seats in the next election. But despite his monumental loss, Goldwater went on to serve three more terms as a Senator, and is often credited with revitalizing the modern conservative movement.