In 1964, the GOP’s deep fissures contributed to Johnson’s crushing victory. But ultimately the forces of Northeastern moderation that resisted Goldwater lost control of the party to the Sunbelt conservatives that elevated him. Ronald Reagan, softening some key elements, followed a Goldwater-like ideological and geographic path to victory 16 years later—but at the price of defining the GOP in ways that eventually alienated the Northeastern and West Coast states most skeptical of that agenda. Goldwater’s “Southern strategy” of courting white Dixie conservatives, later reinforced by Nixon and Reagan, also lastingly alienated African Americans.

The story is similar for the modern Democratic nominee who most divided his party: George McGovern in 1972. McGovern prefigured a culturally liberal Democratic coalition that would mobilize young people, minorities, and white professionals—the coalition that, decades later, twice elected President Obama. But the widespread defections McGovern faced in his landslide defeat by Nixon—when the AFL-CIO refused to endorse him and former Texas Governor John Connally led a robust Democrats for Nixon organization—also foreshadowed his party’s later retreat among the white working-class and in the South.

The GOP’s Trump divide could herald another reconfiguration. Like Goldwater and McGovern, Trump represents a breakthrough victory for a rising party faction, in his case working-class whites drawn to his racially barbed nationalism. And like those predecessors, Trump could also precipitate historic losses among voters his party had previously relied upon, like college-educated whites, or hoped to add, like Hispanics and other minorities. If Goldwater and McGovern are any guide, the aftershocks of Trump’s insurrection will rattle and reshape the GOP long after November—win or lose.