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In the mid-’60s, Marshall McLuhan offered his famous delineation of “hot” versus “cool” media. To oversimplify and put it in contemporary terms, hot media would be the infomercial salesman barking at you “Wait, there’s more!” in a 3 a.m. cable-TV spot. Cool media would be a storytelling podcast, inviting (and requiring) the listener to fill in the details of imagined scenes beyond what the narrator spells out.

That Kennedy was cool—not just in his look and personality but also in his approach to politics and persuasion—was one of many marker points in our political history. Obviously, not all politicians who came after Kennedy could match his cool, or even want to try. (As a rule, Americans tend to choose as the next president someone seen as correcting the flaws of the current one. This often leads to our sequence of temperamental and stylistic opposites: Ronald Reagan, after Jimmy Carter. Bill Clinton, after the first George Bush. Barack Obama, after the second George Bush. And then …) But everyone who followed Kennedy had to be aware of what he had done and how he had changed the terrain.

Mailer couldn’t have known any of this when he wrote. But he set out the idea that there could be political changes few people fully imagine before they occur—but that seem almost inevitable once they have happened. Sixty years after Kennedy’s convention, I think we may have seen another such shift.

Traditional conventions, with thousands of participants, scores of speakers, and countless opportunities to punditize and to schmooze, have been beloved by two kinds of people. Actually, they’re one kind—those whose business takes them to conventions—divided in two. One group is reporters who, like me, love the idea of seeing parts of history directly, with our own eyes, while mingling with others who share that passion. I consider myself lucky to have seen, in person, moments as consequential as the young Barack Obama making his debut at the Democratic convention in Boston 16 years ago, and the triumphant Donald Trump giving his acceptance speech in Cleveland four years ago. The vibe in each room was powerful and unforgettable, in their very different ways. (The group around me on the convention floor in Cleveland spent most of the evening chanting “Lock her up!”)

The other group is the participants—elected officials, staffers, volunteers, hangers-on, those already famous and those getting their start. People who go to conventions go precisely because of their messy spectacle and sprawl. What we love about conventions we would have loved if we’d been there to hear William Jennings Bryan give his “Cross of Gold” speech at the Democratic convention in 1896, or to watch Barry Goldwater and Nelson Rockefeller duke it out at the Republican convention in 1964.

But most people are not like us. Most have viewed the hot, sweaty, noisy, unsubtle conventions as inferior forms of entertainment, as out of date as William Jennings Bryan. Coverage hours have dwindled, and audiences have shrunk.

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