The indictment of former President Donald J. Trump is an unprecedented political event that may have enormous consequences for democracy.

It’s also, effectively, a season premiere.

After a brief hiatus, The Trump Show is back. Americans, ready or not, are now along for another roller-coaster ride with a protagonist whose pre-eminence in the media universe had begun to fade.

Banned from Twitter, Mr. Trump’s outbursts and grievances had stopped shaping the news cycle. Out of office, he became inherently less newsworthy. He even vanished from Fox News, his usual television home, for about four months beginning in November.

Now Mr. Trump has well and truly returned. He turned up on “Hannity” this week, railing against the “fake news” media. His posts on Truth Social, usually ignored in day-to-day political coverage, are circulating widely in the press. Gov. Ron DeSantis of Florida, after gaining some momentum with Fox News pundits and Republican leaders, is temporarily off the collective front page.

Thursday ended in a cliffhanger — the exact criminal charges against Mr. Trump remain unknown — and new episodes are already on the horizon: Mr. Trump is potentially facing several more indictments. And there’s next Tuesday’s equivalent of a sweeps week special, when Mr. Trump is expected to be photographed, fingerprinted and possibly handcuffed at a Manhattan courthouse. The former president has been strategizing his facial expressions for the made-for-TV moment.

Even the supporting cast from The Trump Show heyday is getting into the action. Michael D. Cohen, Mr. Trump’s hangdog former lawyer, is a key witness in the Manhattan district attorney’s case. Stormy Daniels, the adult film star at the center of the indictment, drew blockbuster ratings on “60 Minutes” in 2018. On Friday, she was scheduled to be interviewed by the anchor Piers Morgan, although she canceled minutes before the appearance was set to air.

Reboots are popular these days in the television business. Network executives have learned that viewers respond to familiar characters from the past.

The Nielsen ratings for Thursday’s breaking coverage of the indictment offered a case in point.

Cable news viewership dropped after Mr. Trump left office. The news of his criminal charges turned that right around. In prime time, Fox News drew an average of 3.3 million viewers — a 34 percent bump from its usual audience in the time slot. CNN had 1.2 million viewers, double its year-to-date average. On MSNBC, 2.5 million people watched, a 78 percent increase.

MSNBC benefited from the impromptu return of its star anchor Rachel Maddow, who last year reduced her hosting schedule to once a week. “I am not usually here on a Thursday night,” she told viewers after news of the indictment leaked. “But, you know, things happen. Deep breath, everybody.” (Ms. Maddow was scheduled to be back on MSNBC on Friday evening, too.)

Another aspect of The Trump Show is that it can blot out the story lines of the former president’s political rivals.

Former Vice President Mike Pence agreed earlier this week to appear on CNN on Thursday night, presumably to draw attention to his own prospective bid for the presidency. Wolf Blitzer’s first question was about the indictment, and Mr. Pence’s full-throated defense of the former president, his rival for the Republican nomination, ended up as the interview’s viral moment. (Mr. Pence called the indictment “an outrage” and “a political prosecution.”)

Mr. DeSantis, who has been under sustained attack from Mr. Trump and his allies, was urged recently by some conservatives to expand his media appearances beyond Fox News and start punching back. “If I were Ron, I would start talking,” the Fox News host Jesse Watters said the other day.

Mr. DeSantis did manage to earn headlines on Thursday — by pledging that his state “will not assist” if the New York authorities try to extradite Mr. Trump from Florida. He also called Mr. Trump’s indictment “un-American” and derided the Manhattan district attorney, Alvin L. Bragg.

Martin Kaplan, who runs the Norman Lear Center for media and society at the University of Southern California, evoked the Hollywood term “tent pole show” to describe the glut of Trump programming.

“It holds up the business model of the media,” Mr. Kaplan said in an interview. “No matter how sick of Trump we are, we can’t take our eyes off him. Especially if it looks like the clown car might crash.”

For his part, Mr. Trump has long enjoyed taunting journalists with the idea that their industry’s success was predicated on the seemingly bottomless interest in his life.

“Newspapers, television, all forms of media will tank if I’m not there, because without me, their ratings are going down the tubes,” Mr. Trump told The New York Times in 2017, musing on why he believed the news media would support his re-election efforts. He added, “So they basically have to let me win.”

Mr. Trump lost the 2020 election. But he is poised to remain front and center in the media in the days and weeks to come.

Bret Baier, Fox News’s chief political anchor, said on the air on Thursday that the fallout from the indictment “further divides the country, whether you like the former president or don’t.”

Then he extended an invitation to a certain viewer at home.

“I’d like to put in the call right now,” Mr. Baier said. “If the former president would like to phone in, we’d love to have his reaction to this news tonight.”