The Daisy Girl

BOOM! That is the sound of LBJ's demolition of Barry Goldwater in 1964. It's also the sound of the now infamous "Daisy Girl" ad. In it, a little girl is picking peddles off a flower. The next moment, she is vaporized by a mushroom cloud. The implication: Goldwater would lead America into a nuclear conflict with Russia. The Dems even co-opted Goldwater's campaign slogan "In your heart, you know he's right." They changed it to "In your Heart, you know he might." Goldwater's policies would eventually get Ronald Reagan elected president, but in 1964, they seemed extreme. Ironically, LBJ would be the one to lead the nation to war unnecessarily.
The 1960s were the halcion days of liberalism and Goldwater was a reaction to it. During his nomination speech, he said "extremism in defense of liberty is no vice." Richard Nixon said he knew the election was over at that point. The Dems turned that diddy around on Goldwater. They said that now even Goldwater knows he's an extremist.
Most of the negative campaigning was probably academic. Lyndon Johnson was the incumbent president in 1964 and was running as the heir to Kennedy's "Camelot." The nation was still in mourning over Kennedy's death and LBJ played on that sympathy.
As a result of Goldwater gaffes, skillful Democratic portrayals of Goldwater, and public sympathy following JFK's death, Johnson won 61%- 39% in the popular vote and 486-52 in the electoral college. Goldwater won his home state of Arizona and the Deep South. The South was angry at LBJ's passage of the Civil Rights Act. It was the beginning of the end for the Dems in the South.
Goldwater remained in the Senate until 1987. It was Goldwater that got Nixon to resign in 1974. It was Goldwater's libertarianism that helped lead to the rise of the right and Ronald Reagan.
Johnson served as President until 1969. His Great Society made him the last reform president before George W. Bush. Like Bush, an unpopular war combined with policies of debatable results, made LBJ very unpopular. Unlike Bush, he decided not to run for re-election.