At a televised charity gala in Los Angeles this week, the actor Samuel L. Jackson stepped to the podium to deliver what organizers expected would be a routine appeal on behalf of arts education. Instead, he introduced a nine-second audio clip that, by the end of the evening, had ignited a new round of public dispute with former President Donald Trump and spread rapidly across social media.

The event, held to raise funds for arts programs in public schools, was broadcast live and attended by donors, performers and civic leaders. Mr. Jackson, scheduled to speak briefly between musical acts, began with customary thanks to teachers and patrons. He spoke about discipline — the discipline to listen before reacting, he said — and about the responsibility that comes with a public platform.

Then he reached into his jacket pocket and produced a small flash drive.

According to the broadcast, Mr. Jackson told the audience he wanted to play a short recording. He did not specify its origin. Moments later, an audio clip filled the ballroom. The voice, identified by Mr. Jackson as Mr. Trump’s, spoke in measured tones about crowds and critics, suggesting that loud audiences were easily influenced and that detractors should be managed so they did not “infect the story.”

The recording contained no profanity or explicit slurs. Its force lay instead in what listeners interpreted as a note of private contempt. The room, which had been festive moments earlier, fell notably quiet.

“That,” Mr. Jackson said after the clip ended, “is what power sounds like when it thinks it’s alone.”

Within minutes, the broadcast shifted. Producers patched in a live remote appearance by Mr. Trump, who responded forcefully. He called the audio “fake” and “edited,” accused Mr. Jackson of seeking attention and criticized the network for airing the segment. Speaking over attempts by the host to interject, Mr. Trump characterized the episode as a political stunt.

Mr. Jackson, maintaining a measured tone, posed a single question: If the clip was fabricated, what had actually been said? Mr. Trump did not repeat the language heard in the recording, instead pivoting to broader attacks on media coverage and ratings. The exchange ended abruptly when the remote feed cut out, leaving viewers uncertain whether Mr. Trump had hung up or the producers had ended the call.

By morning, the nine-second clip — along with excerpts from the tense on-air exchange — had circulated widely online. Supporters of Mr. Jackson praised the actor for what they described as a restrained and strategic response to days of online taunts. Allies of Mr. Trump questioned the authenticity of the recording and demanded to know its source, arguing that context was missing.

Representatives for Mr. Trump did not immediately provide additional comment beyond his on-air remarks. A spokesperson for the event’s organizers declined to discuss how the clip had been obtained, citing privacy concerns and potential legal sensitivities.

The confrontation followed several days of pointed comments by Mr. Trump on social media, where he had criticized Mr. Jackson’s acting career and dismissed him as “overrated.” Mr. Jackson had largely refrained from engaging directly, responding in one televised interview with a joke that he preferred to “look at my bank account and laugh.”

Media scholars say the episode illustrates how entertainment venues have become stages for political accountability — or political theater — in an era when viral moments can eclipse formal press conferences.

“Celebrities are increasingly acting as intermediaries in political discourse,” said one communications professor who studies media strategy. “They can introduce material in environments that feel less scripted than traditional news settings. But that also raises questions about verification and editorial standards.”

It remains unclear when or where the audio clip was recorded. Without independent authentication, its provenance — and completeness — cannot be established. Audio experts note that brief excerpts, especially those presented without context, can be difficult to evaluate conclusively.

Still, the exchange tapped into longstanding debates about authenticity and trust. Mr. Trump has often argued that he is unfairly targeted by edited recordings and selective leaks, while critics contend that his own unguarded remarks have repeatedly fueled controversy. The dynamic has become a familiar feature of American political life: allegation, denial, amplification.

Mr. Jackson, for his part, returned the evening’s focus to arts funding after the exchange concluded. He spoke about the importance of creative expression in schools and the power of language to shape civic culture. He did not revisit the audio in his closing remarks.

Whether the nine-second clip will have lasting political impact is uncertain. Brief, emotionally charged media moments often burn brightly before fading. Yet the episode underscores how quickly the boundaries between entertainment, activism and political confrontation can blur.

In a media landscape defined by immediacy, a flash drive held aloft at a charity gala can become, within hours, a national talking point — less for its duration than for the questions it leaves unresolved.