For years the National Football League has been the uncontested king of media in an age of fragmentation. But in 2016, it seems to have run into an even greater force for absorbing the nation’s attention: a presidential election, featuring Donald Trump. After years of steady growth, the NFL’s average television audience fell 8 percent from the previous season.

After the election, the NFL’s ratings perked up a bit, but were still flat-to-down through the end of the season and even through this past weekend. The audience for Saturday night’s playoff game between the Detroit Lions and the Seattle Seahawks was 20 percent below first Saturday night playoff game of 2015. At best, televised football is no longer a growth industry, but merely a strong business that has peaked. At worst, this is the beginning of a period of steady decline for the one thing on traditional television that was never supposed to waver.

Last fall, news analysts converged on NFL’s diminished ratings like detectives at a crime scene. Was the culprit the presidential election? Or did a string of yawners on Thursday Night Football dilute the quality of the games? Was Colin Kaepernick making people mad? Were the concussions?

It now seems that the NFL is the victim of two cultural phenomena, both of which have implications that are deeper than football.

First, the atomization of entertainment has finally reached American sports. The Internet ransacked the music album by giving each song a download button and unbundled newspapers by giving each article a URL. But sports too are now the victim of  two kinds unbundling. First, younger audiences are abandoning cable TV and, therefore, live sports. According to Matthew Ball, head of strategy at Amazon Studios, Americans under the age of 30 now watch almost 50 percent fewer hours of traditional TV than they did in 2010. More subtly, it’s simply easier than ever to watch football now without technically “watching football”—by finding highlights on Twitter and on sports websites. Why spend four hours on the couch when you can get on with your life and catch the most alluring moments in 60 seconds in line at Starbucks?

The second factor is what you might call the superstar effect. To sustain an audience of tens of millions of weekly viewers, the NFL is principally in the business of minting football stars, whose storylines they can follow week to week, like episodes of a favorite scripted television show. The proof is in the numbers. The few 2016 games that exceeded last year’s audience had the biggest recognizable stars and rivalries. Televised games with star quarterback Aaron Rodgers outperformed their 2015 counterparts, and this Thanksgiving’s showdown between the Dallas Cowboys and Washington Redskins was the most-watched NFL regular season game since the 1990s.

Sports are not so different from film. What national audiences desire above all are heroes, compelling challenges, and sequels. But the NFL’s universe of superheroes is surprisingly sparse at this particular moment. Consider a commercial proxy for the league’s biggest stars: the players with the most corporate endorsements in 2015. In just two years, the list has been decimated with injuries, retirements, suspensions, and disappointments. Commercial king Peyton Manning has retired, and so has candy king Marshawn Lynch. JJ Watt is injured, and so is Tony Romo. Drew Brees has missed the playoffs for a third straight year. Eli Manning has been a below-average quarterback since the middle of the Obama administration, while Andrew Luck and Russell Wilson have been alternately brilliant and confounding. Tom Brady remains transcendent, but the league puzzlingly celebrated his transcendence by making him the first citizen to be prosecuted under Boyle’s Law.

Compare this list with the NBA’s list of endorsement leaders. Basketball’s established and ascendant stars (pick your favorite: LeBron, Steph, KD, Harden, Russ, the Brow, the Greek Freak ...) are healthy, in their primes, and mostly playing for competitive teams. The Christmas Day 2016 matchup between the Cleveland Cavaliers and the Golden State Warriors matched the highest-rated holiday game in four years. If sports were stocks, the NBA, despite the smaller market cap, would be the consensus buy.

Here is the bright side for the NFL. Football’s audience is older than basketball’s and less sensitive to cord-cutting, and it’s unlikely that they’re poised to abandon the NFL for any other entertainment on their cable bundles. The Fox News Channel’s Sunday afternoon lineup is not quite must-see. What’s more, if the NFL is in relative decline, it is still TV’s champion in absolute terms. Even its average games attract millions more viewers than a Christmas Day bonanza for the NBA.

So, one might argue that the NFL’s woes are relative. But relative woes matter. Television networks and distributors have committed $50 billion to the NFL until the early 2020s. If audiences continue to sneak away from NFL Sunday, it could hasten the inevitable shift of billions of dollars of advertising to video entertainment’s future home on social-media feeds. (The most popular replacements for traditional TV, like Netflix, Amazon Video and HBO Now, don’t yet accept advertising.)

In short, the atomization of content is pushing audiences away from television just as the locus of cultural superstardom is shifting to basketball. Together it suggests that the NFL Sundays may have peaked as a cultural symbol of American entertainment.