In the months-long lead-up to Monday’s combined event, Kamala Harris did a town hall; Cory Booker did a town hall; Bernie Sanders did a town hall; Elizabeth Warren did a town hall; John Hickenlooper did a town hall; Tulsi Gabbard did a town hall; Howard Schultz did a town hall; Pete Buttigieg did a town hall; Amy Klobuchar did a town hall. There have been many more. Each appearance has tested not only a given candidate’s stances on some of the issues that will be at play in 2020, but also broader questions: What does political charisma look like now that the definition of that quality may finally be expanding? What does an American leader act like in the year 2019?

The town halls work, basically, like this: They put presidential candidates and potential voters together in a single room, to exchange ideas—a mass-mediated version of the flesh-pressing politics that used to be, and in some formats remains, the American norm. In CNN’s version, members of the audience, preselected for the opportunity, ask questions of the candidates, typically reading—and sometimes shaking with understandable nervousness—from slips of paper; the candidates answer the questions; the audience, often, applauds. (The crowds are frequently but not always self-declared supporters of the candidates.) The moderators of the events—CNN anchors such as Tapper, Don Lemon, Erin Burnett, and Wolf Blitzer—occasionally intervene, asking their own questions or following up when a candidate has neglected to answer an audience member’s query.

“Oh, this is fun!” Elizabeth Warren exclaimed during the town hall she held in March. The remarkable thing was that she appeared to have meant it.

For the audience, part of the appeal of the town halls comes from the fact that they can be much more than fun: They are also thoroughly high-stakes for the politicians participating in them. Buttigieg has risen in the polls and in the national conversation in part because of his performance last month at his (first) CNN town hall, before an audience at the South by Southwest festival in Austin. “Buttigieg Feels Momentum After CNN Town Hall, With $600K Raised in 24 Hours,” a headline—from CNN—went, a few days after the March 10 event concluded, citing numbers from a Buttigieg campaign aide. CNN wasn’t alone in that analysis: In a piece explaining the recent “Buttigieg boom,” Vox traced the bump in attention and funding to the South Bend, Indiana, mayor’s “breakout performance at a CNN town hall in early March.” Google Trends agrees with the assessment: It records the search interest in “Pete Buttigieg” as spiking in mid-March—just after he joined Tapper on CNN’s makeshift stage.

The town halls, in that way, can have the feel of a religious ritual: They profess a faith in the power of the political conversion experience. They assume that there are minds, among both studio audiences and those watching at home, that are capable of being changed. Last week, Sanders appeared at a town hall on the Fox News channel, an event co-moderated by the anchors Martha MacCallum and Bret Baier, and the collision of left and right resulted in … a small political victory for the democratic socialist. “By the end of the town hall,” Vox noted, “audience members were booing the occasional Baier or MacCallum follow-up, even doing call-and-response with Sanders.”