At the bar, oftentimes Clement doesn’t so much argue as banter. For much of the Supreme Court’s history, the most effective advocates were dramatic orators like Daniel Webster and Thurgood Marshall. Today, with so many questions being hurled at them from the bench, lawyers have little time for speechifying. “It’s argument by interruption,” former solicitor general Seth Waxman says, “and on balance, that’s a good thing.” The best attorneys are those who can strike a balance between formality and informality, knowledge and modesty, preparation and fluidity. They must be a know-it-all, able to answer any query from a justice, without actually behaving like one—lest they upstage their interlocutors.

Clement delivers his arguments without notes, recalling specific page numbers in the appendices of his briefs from memory. He’s a firm believer in moot courts, and typically holds two before an oral argument, to anticipate any question and respond quickly. “They talk about a quarterback having a sort of clock in their head where if they hold the ball too long they’re going to get sacked,” he says. “When you’re thinking about an answer to a question and you have two answers, one of which is the Platonic form of the great answer but it takes you a minute and a half to get it out, and it’s also something where if you don’t get out the whole thing, it doesn’t really help, and you compare that to an answer that’s 70 percent as good but you can basically get it out in twelve seconds or twenty seconds, I think you’d prefer the second of those two.”

Sometimes it’s hard to tell in the moment how effective his conversational approach can be. In December, the Court heard PPL Montana, LLC v. Montana, a land dispute between a power company and the state that hinged on the question of whether three rivers are navigable. Clement, representing the power company, argued that a river couldn’t be deemed navigable if a boat has to be carried overland for any segment of its journey. Chief Justice Roberts challenged that reasoning, likening it to someone who questions his assertion that he flew from Washington, D.C., to Tokyo by claiming, “No, you didn’t, you flew to San Francisco, then you walked however many yards from one gate to another, and then you flew to Tokyo.” Clement’s rejoinder was instant. “I am not sure I would have the same instinct about common parlance if you had to go from JFK to La Guardia in a cab,” he told Roberts. “And I’m even less sure that you would have the same notion if you had to drive from San Francisco to L.A. to switch planes.” Clement won the case 9-0.