Since Donald Trump’s improbable first win in 2016, pundits have passed countless hours trying to understand how his rise, and the populist movement that powered it, have changed American conservatism. If Ronald Reagan’s Republican Party was, famously, a three-legged stool consisting of social traditionalists, free-market champions, and foreign interventionists, Trump’s MAGA coalition has swelled its ranks, at peril of some internal contradiction. In today’s GOP, Middle East hawks sit next to America First isolationists, former Goldman Sachs executives beside tariff truthers, immigration hardliners with H1B exceptionalists, and Christian Zionists with self-professed antisemites. Over the course of a turbulent decade in and out of power, Trump at times seems to have kept the movement together through sheer force of personality. The offensive against Iran that Trump’s administration launched on February 28 may pose the most significant challenge to the coalition to date. Having campaigned as a “peace president,” Trump now presides over an immediately unpopular war and has angered many in his base who voted to end the foreign entanglements he too claimed to hate. In …