Goldwater started the race about four laps behind. The assassination of JFK meant incumbent Johnson's candidacy had a powerful emotional impetus behind it. On top of this, Kennedy had lowered taxes, lifting us from a recession - and on the Civil Rights front, he'd faced down Governor Wallace in Alabama over integrating the University of Alabama. On foreign affairs, he'd been less than stellar: a google search reveals that "fiasco" is the word that most commonly follows Bay of Pigs.
Back to Goldwater.
His most famous quotation is "Extremism in defense of liberty is no vice, and moderation is no virtue," a paraphrase of Cicero. Another great quotation was, ""Sometimes I think this country would be better off if we could just saw off the Eastern Seaboard and let it float out to sea." (Goldwater was from Arizona.) Nor was Goldwater shy about the possibility of using nuclear weapons, once saying, "Let's lob one into the men's room at the Kremlin as an example."
Democrats paraphrased his campaign slogan, "In your heart, you know he's right," to "In your guts, you know he's nuts." A famous anti-Goldwater ad showed a little girl plucking petals off a daisy followed by a montage of mushroom clouds. Not until the film "Bambi Meets Godzilla" was there another such juxtaposition of innocence and destruction.
After his defeat, Goldwater returned to the Senate and pursued his interests in Hopi "Kachina" dolls (he collected over 430) and UFOs. Goldwater was convinced that the Air Force was covering up knowledge of extraterrestrial visitors, later telling Larry King "They may not look like us, but I have very strong feelings that they have advanced beyond our mental capabilities."
Hearing chilling speculation of smarter-than-Goldwater outer-space aliens, Larry cut to a commercial.
Lyndon Johnson: 486
Barry Goldwater: 52