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.

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

Musk is not about to overtake Trump himself as the dominant figure in the party, to be clear. But the jilted former “special government employee” is uniquely suited to become a chaos agent who could terrorize the GOP — potentially wreaking havoc on Trump’s legislative agenda and the party’s midterm election plans.