As on so many fronts, the portions of the GOP resistant to Trump’s insular vision have managed barely a peep in protest. In the rematch between the ideological descendants of Eisenhower and Taft, only one side is in the ring. “For now, Taft beats Ike—that’s your headline,” said Geoffrey Kabaservice, the author of Rule and Ruin, a history of the modern struggles between moderate and conservative Republicans. “Trump is closer to Taft than he is to Eisenhower, and he has reshaped the party in his image. The forces of Eisenhower and the East Coast internationalist establishment is back on their heels at this point.”

This struggle over the GOP’s foreign-policy direction both echoes and reconfigures the earlier conflict. Then, as now, the GOP’s isolationist elements were dubious of international engagement in all three of its principal forms: military and diplomatic alliance, free trade, and openness to immigration.

The struggle’s most heated confrontations came over international security alliances. Isolationists resisted U.S. involvement in World War II and fumed as internationalists Wendell Willkie and Tom Dewey repeatedly topped Taft for the GOP presidential nominations through the 1940s. Finally, in 1952, Taft seemed poised to seize the party. A free-trade skeptic, Taft opposed the creation of NATO, and while he reluctantly voted for the Marshall Plan to rebuild Western Europe after World War II, he repeatedly sought to reduce it. Yet Taft again failed to claim the nomination after the party’s internationalist forces rallied behind Eisenhower, who entered the race only after Taft would not commit to maintaining the U.S. security guarantee for Western Europe through NATO.

In those years, the GOP foreign-policy debate split mostly along regional and economic lines. Isolationism dominated among Midwestern and Western Republicans, many of them farmers or small-business owners, while the internationalist forces were centered in the east, especially among banking and Wall Street interests already tightly connected to global markets.

Some traces of that older outline persist in the GOP’s differences today, with multinational business representing the strongest internal voice for global engagement. But the principal Republican divide over international involvement is now demographic. Trump’s insular nationalism resonates powerfully with his core constituency of Republicans without a college degree, a group that is almost entirely white. College-educated Republicans, who are also almost entirely white, are generally more skeptical—though even many of them have grown more suspicious of global engagement.

Data provided to me by the Chicago Council on Global Affairs from its most recent annual national survey of American foreign-policy attitudes tracks these patterns. College-educated Republicans, the survey found, were more likely than their counterparts without degrees to view globalization and trade in general and the North American Free Trade Agreement in particular as good for the U.S. But the share of college-educated Republicans expressing such favorable views has declined in recent years, and today it’s far lower than the proportion of college-educated Democrats who view trade positively.