When I called my father back home in Oregon on a recent Sunday, he rattled off his thoughts about the election, the health of his two dogs and queries about holiday plans. But, as the child of a sports-loving house (Go, Ducks!), I was most surprised by what my dad wasn’t talking about on Sunday — football.

He’s not alone in his waning interest. This season, ratings for professional football are down 27 percent across all of the major networks: ESPN, Fox, NBC and CBS, according Forbes. The decline in the ratings underscores a bigger truth that no one wants to face: Nothing lasts forever. And that includes the popularity of professional football, which now may be experiencing the slow, inevitable crumble of a Roman-style empire.

This week, the NFL denied a rumor that the league was reconsidering the fate of “Thursday Night Football,” namely that it was looking to revamp or — gasp — cut back on the sacred media property.

The league said it was “fully committed” to Thursday games, in spite of complaints from players about having to shift too quickly into a midweek game after weekend play, and from fans that Thursday matches have been stale. It’s a slate spread too thin: too many slots, too few compelling matchups. Even so, with a far shorter schedule than professional basketball and baseball, the demand for football has, until recently, remained high.

NFL executives have placed some of the ratings blame on the election. Although NBC’s two games after the election did see a boost, the network’s Kansas City-Denver game had a double-digit drop compared to the same time last year. And, if anything, it seems as though the stress of two unpopular candidates slogging it out would only increase the appetite for diversion. If ever there was a time for gladiator heroes, now would appear to be it.

The fall of Rome seemed unthinkable to people at the time, but inevitable to historians reflecting upon it with the benefit of context. At their height, gladiator contests made war a diversion, thousands charged into majestic amphitheaters, including Rome’s Colosseum, to watch hundreds of gladiators slay wild beasts and each other.

Such was the case until at least the early 5th century AD, as the disapproval of Christians and philosophers grew. When the philosopher Seneca wrote of his impressions of the contest, he was sharp.

“Now finesse is set aside, and we have pure unadulterated murder,” Seneca wrote. “The combatants have no protective covering; their entire bodies are exposed to the blows. This is what lots of people prefer to the regular contests… And it is obvious why. There is no helmet, no shield to repel the blade. Why have armor? Why bother with skill? All that just delays death.”

The rise of Christianity also made the games “culturally unacceptable” because of the money, betting and partisanship involved, said Peter Heather, a professor of medieval history at King’s College in London. So the emperor began to limit the number and scale of gladiator contests until they were phased out.

While the US government is unlikely to ever limit the number of football games, plenty of parents are refusing to let their children play the sport due to the risk of head injuries. The more we learn about chronic traumatic encephalopathy (CTE), a progressive, degenerative brain disease that has plagued scores of professional players, the harder it becomes for many of us to watch the gladiators out on the field. And the more we know about players committing violence off the field, especially against women and children, the more we — like Seneca — turn off altogether.

Football, like boxing, will never go away, just occupy a different role in the American zeitgeist.

Other reasons for football’s demise have been well reported: Our technological advancements leading to the rise of cord-cutting, the mushrooming of electronic sports, and the lure of a second, or third screen (often tied to a fantasy game) are all putting chinks in the modern-day coliseum. A demographic shift, including an increase of soccer-loving fans to the US from around the world, may have broadened sports lovers’ passions beyond the gridiron, too. Increasingly, football fans are arguing that the game is bloated with too much down time. The officiating is clumsy.

For viewers at home, replays and commercials have overwhelmed what game play actually happens. The league lacks a powerful narrative right now, like the Chicago Cubs reversing their 108-year-long hex.

After Christianity killed off gladiatorial combat, Roman fans switched to chariot racing, “which flourished massively as a result,” Heather said. The ascent of the blood-soaked culture of the UFC demonstrates that Americans’ thirst for violence has far from disappeared, but rather migrated to a new Coliseum next door.

The UFC’s worth is estimated at $4 billion or more, with gyms and events popping up worldwide. After a long battle, New York state finally legalized the sport, opening up Madison Square Garden for professional cage fights.

For better or for worse, fans have a new place to celebrate muscles and gore, free from leaden rules and commercial breaks but filled with intense drama and action. Football, like boxing, will never go away, just occupy a different role in the American zeitgeist. The change will be glacial, not instant. And mixed martial arts may just be the chariot-racing alternative of our time.

Mary Pilon is the author of “The Monopolists” and the forthcoming “The Kevin Show.” She worked as a TV producer for NBC Sports at the Rio Olympics