When the late Tim Russert hosted NBC’s “Meet the Press,’’ he was always eager to break news and generate headlines. When something one of Russert’s guests said on his Sunday morning interview program got picked up in newspapers, Russert was a happy man.

By those lights, another host of a Sunday morning interview program, Chris Wallace of Fox News, had a good night Wednesday while serving as moderator of the third and final presidential debate between Hillary Clinton and Donald Trump. For viewers, the debate was revelatory if not exactly reassuring.

After Wallace pressed Trump to say whether he would “absolutely accept’’ the result of the Nov. 8 election if he loses, the GOP nominee responded with an astonishing refusal to say yes or no. “I will tell you at the time,’’ Trump said, adding flippantly: “I’ll keep you in suspense.’’

That answer doubtless jolted many viewers watching at home, and is likely to reverberate throughout the rest of the campaign. Trump’s reply was a remarkable moment in a debate that was relatively substantive, at least compared to the first two — although, like those debates, it was laced with Trump’s trademark ad hominem attacks and problems sustaining coherent answers. Clinton got in some tough digs of her own, prompting Trump at one point to sigh, “Such a nasty woman.’’ Some viewers were doubtless weary of the duo after what would, by night’s end, be a total of 4½ hours in their company over the past month.

Wallace allowed for robust exchanges while keeping a tight rein on the proceedings. The moderator signaled clearly that he would not be steamrolled by either candidate. Introducing one question, Wallace told Trump that at the last debate, “You said several things that were not true, sir’’ about the Syrian city of Aleppo. When Clinton contended that Trump, in the wake of accusations of sexual assault, had said that his accusers “were not attractive enough to be assaulted,’’ Trump blurted out a denial during Clinton’s allotted time to speak. “Her two minutes, sir,’’ Wallace told him firmly. “Her two minutes.’’

The split-screen showed Clinton looking relaxed and smiling often. Trump appeared tense and was often unsmiling, but showed some evidence of debate prep, at least for a while. Wallace mostly forced the candidates to answer his questions. When he raised the issue of the national debt, Wallace asked bluntly: “Why are both of you ignoring this problem?’’ He pressed Clinton to say whether she would consider a “grand bargain’’ that would include benefit cuts and tax increases to shore up Social Security.

At the end of the debate, Wallace sprang an apparent surprise on the candidates by directing them to deliver closing statements on why they should be elected president. Before the debate began, he had enjoined the audience to stay quiet, calling for “silence, please, blessed silence,’’ and he tried to enforce it. Even audience laughter drew a swift rebuke from Wallace. “Hold on, folks,’’ he chided spectators after one burst of applause. “This doesn’t do any good for anyone.’’

Heading into the debate, it appeared that the evening might be consumed with discussions of sexual assault, and that perceptions of Clinton and Trump would be shaped not just by what the candidates said Wednesday night but by what has been said about them in recent weeks.

For Trump, this month has been one long October surprise, as he has denied a spate of sexual assault allegations that followed shortly after a 2005 tape revealed him bragging about such assaults. Trump then sought to resurrect sexual assault allegations against Bill Clinton (which the former president has denied), while raging against the news media and floating conspiracy theories about voter fraud and a rigged election.

For Clinton, October has meant coping with the allegations about her husband and with the WikiLeaks release of ­e-mails hacked from the account of her campaign chairman — ­e-mails that fortified the perception that she tailors her political message to fit her audience.

For TV viewers juggling all these developments as they follow the campaign, it is as if the picture-in-picture feature has been somehow embedded in our collective brain. That response has partly to do with the information overload that is endemic to TV in an era dominated by 24/7 cable news coverage and highly caffeinated pundits who respond to the presence of a microphone the way Pavlov’s dogs reacted to the possibility of being fed.

Fierce though the differences are between Clinton and Trump, and unpredictable though Trump’s behavior during debates has been, it’s almost impossible to focus solely on the candidates during this campaign without flickering images of subsidiary characters competing for head space. Some of the suspense of Wednesday’s debate lay not in how well Clinton or Trump would craft answers to any of the debate’s announced topics — such as foreign policy, the economy, the Supreme Court, even the hot topic of immigration — but rather in seeing how the candidates would respond to the pressure brought about sundry subplots.

The candidates are happy to share the spotlight if it will gain them a tactical advantage. On Wednesday night, Trump brought President Obama’s half-brother, Malik, as well as Patricia Smith, who has said she holds Clinton responsible for the death of her son, Sean Smith, in the Benghazi attack. Clinton, for her part, invited Dallas Mavericks owner Mark Cuban, as well as Meg Whitman, the chief executive of Hewlett-Packard and a former GOP candidate for governor in California.

Don Aucoin can be reached at aucoin@globe.com.