Is Trumpism crashing on the shoals of the Iran war? That is what Christopher Caldwell thinks. Caldwell is a prominent thinker on the right. He’s a contributing editor at the conservative publication the Claremont Review of Books,and he’s one of the people who’ve been trying to define, and even craft, a coherent Trumpism. So his recent article in The Spectator, “The End of Trumpism,” sparked a lot of debate on the right. At the core of this debate are some fundamental questions that I think remain unresolved, despite Trump’s decade-long dominance of the Republican Party: What is Trumpism? Is there Trumpism, or is there just Donald Trump? Caldwell is a contributing writer for Times Opinion and the author of “The Age of Entitlement: America Since the Sixties.” In this conversation, he explains how he understood Trumpism as a movement of “democratic restoration” — and why he believes the Iran war betrays that. And I ask him why he sees the seams of Trump’s base fraying, despite polling that suggests otherwise.