Presidential debates are more often lost than won. The gaffe decides the outcome. Illustration by Christian Northeast

This election’s first Presidential debate will be held on September 26th, the anniversary of the first televised Presidential debate, between Richard M. Nixon and John F. Kennedy, in 1960. Nixon and Kennedy met in a bare CBS studio in Chicago, without an audience; the event was broadcast, live, by CBS, NBC, and ABC. Each candidate made an eight-minute opening statement and a three-minute closing statement. The rules were the result of strenuous negotiating. The very scheduling required Congress to temporarily suspend an F.C.C. regulation granting equal time to all Presidential candidates (there were at least fourteen). Much of the negotiation involved seemingly little things. Nixon wanted no reaction shots; he wanted viewers to see only the guy who was talking. But Kennedy wanted them, and prevailed, with the concession that neither man be shown wiping the sweat from his face. Then there were bigger things. The networks wanted Nixon and Kennedy to question each other; both men insisted on taking questions from a panel of reporters, one from each network, a format that is more generally known as a parallel press conference. ABC refused to call the event a “debate”—the network billed it, instead, as a “joint appearance”—but everyone else did. Sixty-six million Americans watched Nixon scowl, and the misnomer stuck.

This year, the candidates will appear together on the stage of a university lecture hall. The event will be called a “debate” and it will be broadcast live, but it won’t really be a debate and a lot of people will watch clips later. There will be no commercials. Hillary Clinton will be there, overprepared; Donald Trump says the whole thing’s rigged, but he’d be hard-pressed to stay away. “There are those who will say it will be one of the highest-rated shows in television history, if not the highest,” he told the Washington Post. “It will be the most watched event in human history,” former Clinton adviser Paul Begala told me. “Bigger than the moon landing, the World Cup, the Super Bowl, the Olympics, and the latest royal wedding!” It will be gruelling. It will be maddening.

Presidential debates are more often lost than won. The gaffe costs more than exposition gains. It’s easy to practice your kicking; it’s harder to brace yourself for getting kicked. Over the summer, there were rumors that the Clinton campaign had arranged for Alan Dershowitz to play Trump during rehearsals. Nothing but rumors, Dershowitz told me, though he’d love to do it, and he knows how he’d do it, too. “I’d try to provoke her,” he said. “I’d ask about Bill and Monica. I’d ask about her health. Did she bang her head? Does she have blood clots?” The health of the candidates has been an issue during the campaign, proxies for their age: Trump is seventy, Clinton sixty-eight. Trump and Clinton and their key advisers, who like to emphasize their stamina, were kids when Nixon, then forty-seven, debated Kennedy, forty-three. Roger Ailes, who is helping Trump prepare against Clinton, is seventy-six. In the nineteen-sixties, when Ailes was just starting out, he told Nixon that he lost the election to Kennedy because he was lousy on television. He went on to found Fox News but was forced out this summer after an investigation into charges that he’d sexually harassed female employees. It may be that Ailes will advise Trump not to refer to his penis again on national television, but, honestly, who knows? The candidates are old. This era in American politics is new.

A third-party candidate, Gary Johnson or, less likely, Jill Stein, could be invited to this fall’s debates, depending on the polls. Probably there will be chairs, but that’s negotiable. Much, however, is not negotiable. The audience will be silent. Jim Lehrer, who has moderated more Presidential debates than anyone, and who used to be a marine, likes to tell the story of how he’d drill his audiences before each debate. He’d tell them, “If you don’t do what I say, if you cheer or anything like that, I’m going to stop the debate, and I’m going to take the time out of the guy you’re cheering for.” He once got Barbara Bush, sitting in the front row, to agree to write down the names of any infractors. “Trust me, you could hear a pin drop in that place for ninety minutes,” Lehrer says.

Online, though, the audience won’t hush up. In 2008, after Bob Schieffer, the longtime host of CBS’s “Face the Nation,” moderated a debate between Obama and McCain, his staff gave him a sample of tweets. “Someone said I was one of those old duffers in the balcony on ‘The Muppet Show,’ ” Schieffer told me, laughing. “Someone else called me the Brad Pitt of Boca Raton.” Eight years later, the political pother is angrier and meaner. The virtual once imitated the real, what with “bulletin boards” and “chat rooms.” Lately, the real imitates the virtual. “The debate takes the form now of a thread,” Schieffer said, turning serious, when I asked him about the state of political argument. “Someone says something, and someone else says, ‘That’s stupid,’ and the next person says, ‘No, you’re stupid.’ ” Whatever’s going on, it’s getting worse.

This year’s primary debates broke ratings records, and they broke all records for god-awfulness, too. (The two are not unrelated.) The Presidential debates follow different rules, meant to insure fairness, gravity, and substance. The difference can be jarring. It’s like turning on “Cutthroat Kitchen,” expecting to see the host telling the contestants to make ice cream using traffic cones for bowls while wearing dog cones around their necks, only to find that all that’s on is “The Great British Baking Show,” the contestants cheering one another on while making crumpets and scones under a tent pitched in a field of daisies. The reason for the difference is that the primary debates are sponsored and run by the parties and by the media organizations that broadcast and profit from them, but the Presidential debates are governed by the nonpartisan, nonprofit Commission on Presidential Debates. The commission makes the schedule, chooses the venues, sets the rules, and picks the moderators, with an eye to a certain decorum, the state of the Union, the dignity of the office.

The commission is co-chaired by Frank Fahrenkopf, Jr., who used to be the chairman of the Republican National Committee, and Mike McCurry, who was once Bill Clinton’s press secretary. A few months back, I asked McCurry whether he thought Trump, if he got the nomination, would haggle over or flout the rules. McCurry laughed: “I will say that I just ordered ‘The Art of the Deal’ on Amazon.” Since then, Trump has complained about the schedule. “As usual, Hillary & the Dems are trying to rig the debates so 2 are up against major NFL games,” he tweeted in July. “Same as last time w/Bernie. Unacceptable!” Actually, the schedule for this fall’s debates was announced six months before the N.F.L. schedule. Still, the complaint doesn’t come out of nowhere. During the primary season, both Bernie Sanders and Martin O’Malley said the Democratic debates were rigged, since the schedule advantaged Clinton. (There’s no evidence for the charge. Hacked e-mails released by WikiLeaks demonstrate that the D.N.C. favored Clinton in a thousand ways, but, according to PolitiFact, the debate schedule wasn’t one of them.)