It began with Musk complaining about the centerpiece of Trump’s legislative agenda, which the president at first took in stride. Eventually Trump let slip that he was disappointed in his former adviser, prompting Musk to unleash a flood of insults and taunts.

One group that’s hopeful about the Trump-Musk rift: advertisers, who had been in Elon Musk’s crosshairs since exiting X en masse shortly after the billionaire businessman bought the social-media site then known as Twitter.

A knock-down fight between world's the richest person and the most powerful politician is playing out in public view.