Though the party’s heart may have leaned rightward, its head told it back then to nominate a World War II hero and relative moderate, Dwight D. Eisenhower. That all changed in 1964. Aggrieved conservatives became “convinced that they have to take back the party from what they call the Wall Street Republicans, the New York kingmakers,” said Rick Perlstein, author of the 2001 book “Before the Storm: Barry Goldwater and the Unmaking of the American Consensus.” Their prophet was Goldwater – “this cowboy conservative from Arizona,” as Mr. Perlstein told Retro Report – someone who talked loosely about using nuclear weapons and who voted against the landmark Civil Rights Act of 1964.

The rage, which included some menacing of journalists, was plainly visible to an entire nation.

At the 1964 convention, held in San Francisco, Republican moderates refused to go down without a fight. They put forth one of their own, the patrician Pennsylvania governor, William W. Scranton. That gambit failed. Then came a memorable convention speech by another Eastern Establishment patrician, Gov. Nelson A. Rockefeller of New York. He taunted the crowd like someone poking a caged lion with a stick.

“The Republican Party,” he said in tones that alternated between defiance and mockery, “is in real danger of subversion by a radical, well-financed, highly disciplined minority.” Enraged delegates howled. Rockefeller was already hated by many social conservatives for divorcing his first wife and marrying another woman. (This, obviously, was long before the party embraced a thrice-married, credibly accused philanderer.) Theodore H. White, the great chronicler of presidential campaigns, wrote of a woman in the audience shaking her fist at Rockefeller and shouting, “You lousy lover, you lousy lover, you lousy lover!”

The rage, which included some menacing of journalists, was plainly visible to an entire nation. It did not redound to the Republicans’ benefit. “None of us knew how important television was,” J. William Middendorf, who was Goldwater’s campaign treasurer and later a Secretary of the Navy, said to Retro Report. “Americans were seeing these screaming people.”

For his part, Goldwater had zero interest in accommodating the moderates. He dismissed them out of hand with lines that many older Americans remember to this day: “Extremism in the defense of liberty is no vice!” he declared. And, he added, having underlined these words in his own text, “moderation in the pursuit of justice is no virtue!”

The general election proved disastrous for him and his party. “The convention pretty much killed us,” Mr. Middendorf said. “I mean, I had a sinking feeling that it was pretty much over.” Even the choice of a vice presidential nominee, an upstate New York congressman named William E. Miller, proved of no use. Miller left a mark so faint that he capitalized on it a decade later, doing a commercial in which he said no would recognize him if not for his American Express credit card.

And then there was the Johnson campaign’s “Daisy” television commercial. It ran only once, but that was enough. It landed with devastating impact: A little girl counting a daisy’s petals as she plucks them, when suddenly a male voice counts down ominously to zero and to the blinding light and mushroom cloud of an atomic explosion. The unmistakable message was that putting the nuclear codes in Goldwater’s hands would be cataclysmic.

That November, Johnson won 61 percent of the popular vote and took the Electoral College by 486 to 52. Goldwater triumphed only at home, Arizona, and in five Southern states – South Carolina, Georgia, Alabama, Mississippi and Louisiana – that turned on the Democrats because of civil rights legislation. The Democrats also won more than two-thirds of the seats in each house of Congress.

Might this Republican past be a 2020 Democratic prologue should Bernie Sanders become the nominee? That’s a case party moderates are making.

Whatever happens in coming primaries and in November, Mr. Sanders may have already left an indelible mark. After all, one could argue that Goldwaterism prevailed even if the man himself did not. “From Goldwater’s insurgency onward, the die was cast,” the political scientist Larry J. Sabato wrote in Politico Magazine in 2014, “and the GOP has never returned to a moderate platform.”

CLYDE HABERMAN, a regular contributor to Retro Report, has been a reporter, columnist and editorial writer for The New York Times, where he spent nearly 13 years based in Tokyo, Rome and Jerusalem. This article first appeared in Retro Report’s newsletter. Subscribe here and follow us on Twitter @RetroReport.

Further Reading

Goldwater’s NYT obit:

William Miller’s NYT obit:

Miller obit (commercial was in 1975)

The Miller American Express commercial: