“But do you have a plan, other than to beat Trump?” pressed Tyler Davis, 13, channeling Representative Tulsi Gabbard of Hawaii.

Role-playing the presidential contests helps less experienced debaters hone their rhetorical skills, said Hiba Sheikh, 24, the lab’s other leader. It also magnifies differences. In the type of competition the campers practice, called policy debate, judges grade opposing teams, each composed of two debaters, according to the strength of their arguments as well as the evidence they present. “Thinking about presidential debates through a policy debate lens makes you really see what claims they are making and how they are substantiating those claims,” Ms. Sheikh said of the presidential candidates. “And often they’re just not substantiating them.”

One floor away, a lab of 12 varsity debaters looked for parallels. The candidates’ liberal use of ad hominem attacks might not fly in a policy debate round, said Jackie Poapst, the assistant director for George Mason University’s debate team, who led the discussion. But deploying strong opening statements to prime an audience and stressing the far-reaching effects of policy certainly would.

Ms. Poapst’s students watched Wednesday’s debate as a homework assignment. For over an hour, they picked apart performances, zeroing in on effective attacks (Mayor Bill de Blasio of New York and Ms. Gabbard) and key clashes (Senator Kamala Harris of California versus Mr. Biden on health care; Senator Cory Booker of New Jersey versus Mr. Biden on criminal justice).

“It’s impressive just how much more they do than us and how much less they do than us at the same time,” said Timothy Neal, 15, comparing his fellow campers with the presidential hopefuls. “On one hand, we talk about one resolution a year, and they had, like, six of those in that one debate,” he added, using the term for the topic students debate over a 10-month season. “And on the other hand, we talk about one resolution a year, and we aren’t dodging questions and salting each other.”

The presidential debates can also influence the varsity students’ own arguments. In policy debate, students present real-world proposals and actionable plans to enact them. That often means considering shifting political winds. This season’s resolution, that the United States limit arms sales to foreign governments, is complicated by the impending election, said Lola Rogin, 14. “If something political changes, and it could be anything, it changes the trajectory of debates.”