On Hollywood’s biggest night, the joke did not originate from the stage but from a phone.

As the 96th Academy Awards unfolded at the Dolby Theatre, host Jimmy Kimmel paused his monologue to read aloud a social media post from Donald Trump criticizing him as “the worst Oscars host ever.” The audience laughed. Then Mr. Kimmel delivered a line that ricocheted across the internet within minutes, thanking the former president for watching and quipping about whether it was “past your jail time.”

The exchange was vintage late night: nimble, irreverent and calibrated for virality. But it also underscored a deeper dynamic that has defined the Trump era — a struggle over attention, image and narrative control between a political figure who thrives on spectacle and comedians who have made him a recurring character in their nightly scripts.

For Mr. Trump, live television has long been both a platform and a battleground. During his presidency and after, he frequently attacked entertainers and journalists who mocked him, often in real time. For hosts like Mr. Kimmel and Stephen Colbert of The Late Show with Stephen Colbert, those attacks have become raw material.

At the Oscars, the tension played out before a global audience. Producers reportedly advised Mr. Kimmel to ignore the post. Instead, he read it in full, allowing its tone to hang in the air before responding with a single, cutting aside. Reaction shots captured actors laughing in disbelief. By the following morning, headlines from entertainment and news outlets alike framed the moment as a rare instance of a sitting president being mocked, live, on one of television’s most prestigious stages.

The back-and-forth did not end there. On the next episode of Jimmy Kimmel Live!, Mr. Kimmel treated the president’s post as a trophy of sorts, holding up his phone as if it were an award. “I’ve got my Oscar now,” he joked, suggesting that a presidential rebuke had become a badge of honor.

Meanwhile, Mr. Colbert, whose tenure at CBS has been marked by sharp monologues aimed at Mr. Trump, continued his own brand of satire. Over the years, he has used the former president’s interviews and rally remarks as fodder, replaying clips and punctuating them with wry commentary. In one widely discussed segment, he led his audience in a chant that inverted a slogan once used against Mr. Trump’s political opponents, turning it back toward its originator.

Such moments reflect how late-night television has evolved into a hybrid of comedy and political commentary. Where earlier hosts tended to keep politics at arm’s length, contemporary figures often engage directly, framing events through humor that doubles as critique.

Mr. Trump, who built his public persona in part through reality television, appears keenly aware of the power of the camera. His responses to mockery often come swiftly, whether through interviews or posts online. But in the age of instant replay and social sharing, each retort can extend the life of the joke.

The dynamic is not new. Presidents have long been lampooned, from Gerald Ford’s stumbles to George W. Bush’s verbal slips. What distinguishes the current moment is the immediacy. A post from the White House residence can be read aloud minutes later on live television, transformed into a punchline before the credits roll.

The rivalry has also generated tangible outcomes. After particularly pointed monologues, complaints have flooded networks and regulators. Mr. Colbert once drew thousands of complaints to the Federal Communications Commission over a segment that critics deemed too crude. The commission ultimately took no action, and ratings for his show rose.

For supporters of the hosts, such episodes demonstrate resilience — proof that satire remains a check, however symbolic, on political power. For Mr. Trump’s allies, they are evidence of cultural institutions aligned against him.

Yet the exchanges also reveal something subtler: a contest over who commands the narrative. Mr. Trump’s political brand has relied on dominating airtime, setting the agenda and forcing opponents to respond. Late-night hosts, by contrast, wield timing and irony, reframing his words for audiences primed to laugh.

At the Oscars, that contest unfolded in miniature. A presidential insult became a monologue beat. A global broadcast became a feedback loop. The president’s attempt to diminish a host’s performance arguably amplified it.

Comedy does not change policy. It does not pass legislation or overturn elections. But it can shape perception. When a joke lands at the expense of a powerful figure, it chips at the aura of inevitability that leaders often cultivate.

In the days after the ceremony, clips of Mr. Kimmel’s response continued to circulate, accompanied by commentary about the unusual spectacle of a president sparring with an awards-show host. The moment joined a growing archive of late-night exchanges that blur the line between entertainment and civic discourse.

For Mr. Trump, who has rarely ceded the spotlight willingly, the episode was another reminder that in an era of ubiquitous screens, the stage is never entirely his.