This excellent commentary from Ronert Mann writing in Politico outlines the idea that Goldwater failed to win the White House because he was perceived as, if not actually, an extremist. Mann's central contention, and it is the correct one, is that any candidate who strays from the middle can be easily defeated by an adversary who portrays themselves as moderate.
But if ever there were a time to roll the dice and elect someone other than the most bland candidate, isn't that time right now?
Goldwater was passionately anti-communist and his zealousnesss to thwart Soviet imperialism likely cost him the presidency. But he was also a proponent of the gold standard, smaller government, and a strong dollar. In retrospect, if we had elected this "radical" forty years ago and he had turned out not to be threat the left had made him out to be, wouldn't we better off today?
Sensible libertarian views on nearly everything- except foreign affairs.