The Commission on Presidential Debates has scheduled three match-ups between Trump and former Vice President Joe Biden, the first set for Sept. 29. Noting that many states will have already begun early voting by then, the Trump campaign last week sent a letter to the commission asking that a fourth debate be added in early September — or, barring that, that the final debate be moved up from Oct. 22.

“A debate, to me, is a Public Service,” Trump tweeted on Thursday. “Joe Biden and I owe it to the American People!” The commission rejected the request, insisting such a move was unnecessary. The truth is that scheduling is way down the list of problems with presidential debates, in this election cycle or any other. Debates are indeed a public service, providing voters a rare opportunity to see the presidential contenders side by side and take their measure for an extended stretch of time in a high-pressure setting. But in practice, the events have degenerated into media spectacles, showcasing much that is wrong with both electoral politics and journalism.

Designed to maximize ratings — and, increasingly, the number of viral moments — the debates are light on meaningful discourse and heavy on ginned up conflict, regurgitated talking points and cheap zingers. With their countdown clocks, twitchy graphics and breathless hype, the media hosts too often package the events like pro wrestling matches. The moderators often focus more on burnishing their personal brands than on facilitating discussion.

This year’s dynamic is complicated by Trump, whose relationship with truth is tenuous at best. With his penchant for prevarication, his desire to turn every appearance into a carnival, his defensiveness about his job performance and his growing desperation to improve his poll numbers, the debates seem bound for a new low.

Much research has been done, and many recommendations made, on how to improve the debates. One starting point is to rein in the media outlets that host them. Networks need to tone down the gladiator vibe. The campaigns are not helpless bystanders. They should have a say in the basic tone of the proceedings. (Of course, Mr. Trump seems just as likely to advocate even gaudier showmanship.)

The role of the moderators is a perennial area of concern. “The single largest criticism of the debates centers on the inability of moderators to do their job,” noted a 2015 report by a debate-reform working group put together by the Annenberg Public Policy Center. The most common complaints were that the moderators play favourites and that they “either do not have the skills to control the candidates or to call them on ‘non-answers.’” This critique is as relevant as ever.

Moderators are in a tough spot. If they let candidates bluster on or wander too far afield, they get criticized for losing control of the debate. If they cut candidates off and strictly enforce time limits, they get criticized for being too intrusive.

But, in general, moderators need to avoid becoming part of the story. They should encourage direct interaction between the candidates, even if that means sitting back and missing out on the occasional follow-up question. Debates are not meant to be modified news conferences or interviews. The Annenberg report recommended cutting moderators out of the action as much as possible. With the particular challenges that Trump poses, of course, that may call for some adjustments.

The president has made clear that he will say anything, without regard to the truth. The debate hosts and moderators need to have multiple systems in place to deal with this and be willing to call him out. Real-time fact-checking resources should be beefed up, along with morning-after analyses. As an additional check, particularly egregious lies spread in one debate could be revisited in subsequent ones, with the candidates asked to respond.

The basic debate structure could use some tweaking as well. The common format of allowing each candidate 60 to 90 seconds to answer, followed by 30 seconds for rebuttals, is too rigid and provides insufficient time for thoughtful responses. It pushes participants to give every question equal time.

One proposed alternative is the chess clock model, in which each candidate would receive a total of 45 minutes, which would tick down whenever he or she spoke. Within reasonably broad parameters, a candidate could devote different amounts of time to different questions, for instance, spending twice as long on climate change as on decriminalizing border crossings — or vice versa.

Another Annenberg suggestion for helping candidates define their priorities: Give each contender two or three topics in advance, for which they would prepare meaty four-minute statements, and their opponent would prepare equivalent rebuttals. Topics could be determined variously by the candidates, the moderators and the voters.

Organizers really ought to consider losing the live audiences — even after crowding into a college auditorium is no longer a public health hazard. All the jeering and cheering encourages the candidates, and even some moderators, to play to the crowd. The crowd reaction, in turn, influences how the home audience processes the event. The entire set up lends itself to the kind of stunt Trump pulled at a 2016 debate with Hillary Clinton, to which he invited several women who had accused President Bill Clinton of sexual misconduct — and tried to seat them in his VIP box next to the former president.

The presidential debates don’t have to be such circuses. The public and the candidates ought to demand better.