A related question is whether realism is actually part of the Republican Party’s intellectual DNA. Philip Zelikow says no, not really:

As a historian, I think one of the more remarkable things about the Nixon-Kissinger approach to great power relations and détente is actually how anomalous it was in comparison to the record of America’s international rhetoric and goals. That administration’s relative indifference to the character and governance of the other states in the international system has no equal in any other other U.S. administration of the last 120 years.

The reasons for the Nixon-Kissinger anomaly are probably to be found more in the Vietnam War challenge and the upheavals around the world bucking the general ossification of the cold war system. There was a global retrenchment among governing elites across the globe in the early 1970s (a thesis Jeremi Suri has introduced in the last chapters of his Power and Protest). These more particular explanations seem more useful than arguments finding in this period the recurrent flowering of some long-running but dormant “realist” strain in America’s collective thought.

Point taken. But it’s worth remembering that Nixon’s foreign policy accomplishments were substantial, and that the Nixon Administration, as a practitioner of grand strategy, compares favourably to almost any other US administration of the post-WWII era. Even if Nixon/Kissinger-style realism represents a minority tradition in Republican foreign policy thinking, it may still be a tradition worth re-examining.