Early on a recent morning, in a suburb of Fort Lauderdale, Fla., the publicist Mitchell Jackson started his day as he normally would, by taking his phone from the nightstand and scrolling through it. The subject line of an email grabbed his attention: “Financial Times article — lawsuit from Macrons.”

It came from a Financial Times reporter who was requesting comment from Mr. Jackson about some breaking news: The French president, Emmanuel Macron, and his wife, Brigitte Macron, had just filed a 22-count defamation lawsuit against Mr. Jackson’s biggest client, Candace Owens, the right-wing podcaster. The Macrons accused Ms. Owens of falsely and repeatedly stating on her show that Mrs. Macron is a man.

Mr. Jackson, 33, hunkered down in his home office and hopped on a call with Ms. Owens and her team to drum up a public relations plan. He put on Black Sabbath and sipped Earl Grey tea as he read through the more than 200-page lawsuit. He paced the room as he rolled calls with reporters from Reuters, The Washington Post, The New York Times and TMZ.

At 12:24 p.m., he hit send on a press statement he had written for his client. The tone was combative.

“Candace Owens is not shutting up,” it read. “This is a foreign government attacking the First Amendment rights of an American independent journalist.”

That evening, when the Macrons’ lawyer appeared on the CNN program “The Lead With Jake Tapper,” Mr. Jackson was still on the phone. He had spoken — on the record, off the record, on background, on deep background — with over 30 journalists.