Jelani Cobb in The New Yorker:
One of the oldest imperatives of American electoral politics is to define your opponents before they can define themselves. So it was not surprising when, in the summer of 1963, Nelson Rockefeller, a centrist Republican governor from New York, launched a preëmptive attack against Barry Goldwater, a right-wing Arizona senator, as both men were preparing to run for the Presidential nomination of the Republican Party. But the nature of Rockefeller’s attack was noteworthy. If the G.O.P. embraced Goldwater, an opponent of civil-rights legislation, Rockefeller suggested that it would be pursuing a “program based on racism and sectionalism.” Such a turn toward the elements that Rockefeller saw as “fantastically short-sighted” would be potentially destructive to a party that had held the White House for eight years, owing to the popularity of Dwight Eisenhower, but had been languishing in the minority in Congress for the better part of three decades. Some moderates in the Republican Party thought that Rockefeller was overstating the threat, but he was hardly alone in his concern. Richard Nixon, the former Vice-President, who had received substantial Black support in his 1960 Presidential bid, against John F. Kennedy, told a reporter for Ebony that “if Goldwater wins his fight, our party would eventually become the first major all-white political party.” The Chicago Defender, the premier Black newspaper of the era, concurred, stating bluntly that the G.O.P. was en route to becoming a “white man’s party.”
But, for all the anxiety among Republican leaders, Goldwater prevailed, securing the nomination at the Party’s convention, in San Francisco. In his speech to the delegates, he made no pretense of his ideological intent. “Extremism in the defense of liberty is no vice,” he said. “Moderation in the pursuit of justice is no virtue.” (He delivered that famous line shortly after the delegates had defeated a platform plank on civil rights.) Goldwater’s crusade failed in November of 1964, when the incumbent, Lyndon Johnson, who had become President a year earlier, after Kennedy’s assassination, won in a landslide: four hundred and eighty-six to fifty-two votes in the Electoral College. Nevertheless, Goldwater’s ascent was a harbinger of the future shape of the Republican Party. He represented an emerging nexus between white conservatives in the West and in the South, where five states voted for him over Johnson.
More here.