Michael Strahan, Robin Roberts and George Stephanopoulos opened Monday’s broadcast of “Good Morning America” laughing over the strains of a 1972 King Harvest tune about dancing in the moonlight – a teaser for a segment about a bright phenomenon known as a “supermoon.”

The trio is supposed to smile. This is, after all, morning television. But things taking place in the world of A.M. TV are enough to set the hosts at all the shows gritting their teeth.

ABC’s sunrise program is the most watched in the nation, and has been locked in a battle for dominance with NBC’s “Today” for several years. “GMA” regularly wins the most viewers while the NBC staple commands the greatest amount of those Madison Avenue cares about, people between the ages of 25 and 54. Recent events could give “GMA” an edge in that ongoing skirmish – even as the A.M. battle has moved to other fronts. The morning-TV terrain has shifted so fast it’s fair to wonder if any of the shows can maintain command over the long haul.

At a time when President Trump’s early-morning tweets can set the news cycle on its head, TV’s morning shows are being forced to adjust, said Nikki Usher, an associate professor at George Washington University who studies the evolution of news.  “The world is in a very intense moment.”

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And so too are TV’s morning mainstays.

Two of the biggest programs in the daypart are without two of their best-known anchors. Matt Lauer was ousted from “Today” last week, and Charlie Rose, fired from “CBS This Morning” last month – both in the wake of allegations of sexual-harassment being leveled against them. In separate statements, the former hosts expressed regret for certain actions while suggesting some accusations were not accurate. At the same time, the broadcast programs are losing viewers. Cable’s morning shows are digging deeply into current events in more avuncular fashion. But the broadcast anchors must appeal to the broadest audience possible, making it hard to engage in the 20-minute long arguments Chris Cuomo has with Trump administration officials on CNN’s “New Day,” or hurl derision at the White House as Mika Brzezinski and Joe Scarborough do on “Morning Joe.”  Trump’s affinity for Fox News Channel makes that network the most likely to get access to the president, giving that outlet a leg up on generating headlines.

In the current era, “people don’t want to go into work and get around the water-cooler and talk about movies or what they are going to get for Christmas,” said Usher. “Morning shows are great for easing people into the morning, but today, easing into the morning is a different kind of easing.”

As the shows grapple with viewers’ increased attention to U.S. politics and world affairs, they must also focus on each other. While many people focus on “Good Morning America” and “Today,” CBS has become competitive in the morning for the first time in years, and the cable programs are taking on new authority. In TV-news circles, producers and anchors are all trying to figure out who NBC might put in place at “Today” opposite Savannah Guthrie, and who might join Gayle King and Norah O’Donnell at “CBS This Morning.” And of course, they have another question:  Might those shows’ audiences wander elsewhere based on those decisions?

Millions of dollars in ad revenue are at stake, along with a broader profile for news divisions at ABC, NBC, and CBS, or the eyeballs at the big three cable networks: Fox News Channel, MSNBC and CNN.  The first two hours of “Today” alone captured more than $500 million in advertising in 2016, according to Kantar, a tracker of ad spending.

Most anchor changes don’t affect ratings levels, said Brian Hughes, senior vice president of audience intelligence at Magna, the Interpublic Group-owned media buying and research unit. “It would be impossible to separate any impact from the organic viewing changes that are already occurring,” he said.

But some TV-news executives sense a growing new battle for viewer attention.  Already, executives at Fox News Channel are mulling the launch of a promotional campaign to lure “Today” viewers to “Fox & Friends,” according to a person familiar with the matter. Meanwhile, executives at another news outlet are telling on-air staffers who might have hopes of joining the NBC or CBS programs that there’s no way anyone will be let out of a current contract.

At CBS, executives don’t feel immediate pressure to fill Rose’s seat, according to a person familiar with the situation. Rose was absent from “CBS This Morning” for part of February and March of this year owing to heart surgery, and the ratings for the show during that time did not create alarm, this person said.

The network appears willing to consider all options for a replacement, including an outsider or a current staffer. Under David Rhodes, CBS News’ president, the network has leaned towards inside promotions, as recently seen when Jeff Glor was named to replace Scott Pelley at “CBS Evening News.” Vladmir Duthiers, Bianna Golodryga and John Dickerson are among the CBS News staffers slated to fill in on “CBS This Morning.”

Rhodes on one occasion seemed willing to give a new face a chance, when he hired Josh Elliott to work at streaming-news outlet CBSN. CBS News and Elliott parted ways under unusual circumstances earlier this year. Leaving the evening-news job open for several weeks after Pelley’s departure may also have sparked new candidates to reach out to the news unit.  CBS News declined to make executives available for comment.

NBC has an event coming up that could buoy a new face at “Today.” NBCUniversal’s coverage of the Winter Olympics is expected to be massive – more than 2,400 hours of coverage in all – and the morning show typically broadcasts from wherever the global games are being held. The Olympics typically give a ratings boost to “Today,” so a new anchor would get much more exposure and could spark new attention for the show.

Whether NBC News can pivot from wrestling with the aftermath of Lauer’s unsavory ouster to filling his role quickly remains to be seen. Hoda Kotb has been anchoring alongside Savannah Guthrie in recent days and Kotb, Willie Geist and Craig Melvin are seen as potential candidates for consideration. NBC News declined to make executives available for comment.

As TV-news staffers gaze at those prime anchor jobs, audiences are viewing the daypart a little differently.

ABC, NBC and CBS continue to command the biggest audiences at wake-up time. “GMA” and “Today” each woo more than 4 million people on average, while “CBS This Morning” gets more than 3.5 million. Cable’s morning audience is smaller. Through November 30, “Fox & Friends” captured an average of 1.59 million; “Morning Joe” 964,000; and CNN’s “New Day” 632,000.

But the crowd advertisers favor most is soaring at the cable shows. “Fox & Friends’” viewership among people between 25 and 54 is up 32% to 367,000 through November 30. The audience in the demo has risen 41% at CNN’s “New Day,” to 227,000. And the category is up 32% at MSNBC’s “Morning Joe” to 223,000, according to Nielsen.

The broadcast networks have shed a slice of that audience. Viewership in the demo is off 12% at “GMA” to 1.36 million; down 15% at “Today” to 1.52 million; and off 10% at CBS to 962,000, according to Nielsen.

The broadcast networks have an opportunity as well. The departures of Lauer and Rose give NBC and CBS the chance to shake things up and recalibrate their programs for current demands. New techniques can lend the decades-old shows a new look and feel. ABC has radically transformed the second hour of “Good Morning America” by letting fans come and sit in the studio, and interact with hosts like Strahan and Lara Spencer.

The shows depend less on one or two people than they did in the 1970s and 1980s. “CBS This Morning” has had three co-anchors since it relaunched in 2012, and “Good Morning America” these days opens with a trio as well. Many of the programs have a bevy of longtime personnel, including Al Roker at “Today” or Amy Robach and Ginger Zee at “GMA” that viewers often embrace as part of a TV family.

“These shows have so many cast members that any one of them is less important to the show compared to 20 and 30 years ago,” said Larry Chiagouris, a professor of marketing at Pace Univeristy. Even so, he acknowledged, new faces at NBC and CBS could spark new interest in their morning programs.

If that’s the case, the “Good Morning America” anchors may want to watch their choice of music in the days to come. Morning anchors who do too much dancing in the moonlight might be too weary to do battle in the dawn.