A UFC bout might have looked like a safe space for Trump. Here’s why it wasn’t.

Even before President Trump arrived at Madison Square Garden on Saturday, his presence was everywhere. For blocks around the arena, police gathered in large groups, and several streets along Eighth Avenue were blocked. People entering the event walked past protesters holding anti-Trump signs and the odd fan in a MAGA hat, sights rarely seen at mixed martial arts events. Once inside, everyone was subjected to close screenings by Secret Service agents.

All night, there was a sense of anticipation and anxiety that went beyond the normal levels for fight night. The crowd was distracted during the early matches. When would he appear, and what would we do when he did?

Around 10 o’clock, a few minutes before the main card was set to begin, there was a stir on the main floor of the arena, and everyone leaped to their feet and looked down to where a large group of men in dark blue suits had appeared. And there he was among them, the president of the United States, standing beside a cage, waving.

The booing began immediately. The music on the loudspeakers was turned up, either to herald Trump’s arrival or to stifle the crowd’s displeasure in reaction to it, but the sound of those boos was overwhelming. A few Trump fans scattered throughout the room cheered, but they were drowned out. Three rows down, a young couple held up a sign that said “Impeach and Remove.” There was no introduction like there had been at the World Series last week, no sense of ceremony or occasion, no video of the president and his sons on the Jumbotron, no “Lock him up” chants — but for a moment, the environment, already full of alcohol and flush with three hours of fights and charged for more, felt volatile.

It was no surprise that a New York crowd would greet Trump with hostility, but there was no guarantee an MMA crowd would. After all, Trump has a long history with the sport. One could even argue that he’d saved it. That was back in February 2001, when the UFC was at death’s door. Years of attacks by politicians and concerned parents had relegated the company and the sport to the darkest corners of the cultural landscape. Zuffa, a company run by Las Vegas casino owners Frank and Lorenzo Fertitta, had purchased the UFC for $2 million one month earlier, and it wasn’t clear they’d ever see that money again. But Trump, who’d played a huge role in turning Atlantic City into a boxing mecca a decade earlier, saw something in MMA and the new owners of the UFC. He opened the doors of his Taj Mahal casino for the first event of the Zuffa era, giving their struggling promotion and its product some much-needed credibility.

Nearly 20 years later, UFC president Dana White returned the favor, singing Trump’s praises at the Republican convention in 2016.

Observers outside the MMA world who had no knowledge of UFC’s past relationship with Trump seemed to expect a warmer reception for the president. People who don’t know the sport assume a natural affinity between Trumpism and MMA: a shared brutishness, a devotion to mindless entertainment and spectacle and cruelty, a safe space for disaffected, angry white men. In Vanity Fair, Jordan Hoffman mocked Trump for ignoring the Museum of Modern Art, the New York Philharmonic and New York City’s many other cultural treasures in favor of watching “people writhe around on canvas and beat the snot out of each other.” The Daily Beast suggested UFC 244 was “The Only Place in New York Where Trump Might Avoid Boos,” and wondered if Trump “sensed that there is something valuable to be mined in the politically incorrect, that sweat and blood can rouse people more viscerally than reason and sentiment, that there is a base to be found in baseness.” Why, critics asked, would MMA fans boo the man who speaks to their hearts with every tweet?

The simple answer is that common conceptions about MMA as a natural home for brutes, bullies, xenophobes, racists, sadists, misogynists, destroyers of common decency and poisoners of young minds are wrong.

It’s true that when the UFC began in 1993, its existence wasn’t easy for humanists and progressives to justify. The original idea behind it — let’s find out which fighting style is the best by pitting them against each other in a cage — was designed to shock, and the UFC thrived off the inevitable controversy, every cry from every politician and family organization swearing that the matches were no better than gladiatorial combat and that its arrival signaled the end of civilization.

The sport’s most powerful critic, the late senator John McCain (R-Ariz.), famously called it “human cockfighting” and helped persuade 36 states to ban it in the mid- to late ’90s.

But then a strange thing started happening. Even as the original deviant thrill of those early events started to fade — and cage fighting was banned by state legislatures, kicked off cable pay-per-view and relegated to small venues in backwater towns — the people actually involved in the sport were learning from those first events and the backlash to them. The UFC marketing team, which had leaned heavily on the slogan “There are no rules” to sell the sport in the early days, now started working with state athletic commissions to find ways to make cagefighting more palatable. Each event in the late ’90s seemed to come with a new rule: first the introduction of weight classes and gloves, then bans on hair pulling, head-butting and groin strikes, and finally the arrival of round time limits.

Meanwhile, fighters and coaches were quietly changing the sport from the inside, experimenting like scientists in a lab. The lesson of the early UFC events had turned out to be not that there was one fighting style that beat all the others, but rather that if you wanted to be a true martial artist, you needed to understand all fighting styles. So while the world was looking elsewhere, these curious fighters and coaches started building a new language, one that took the most effective elements of all the fighting styles of the world and mashed them together. And thus, out of the spectacle of no-holds-barred fighting was born a new sport: mixed martial arts.

Whatever was effective about a particular fighting school was kept and whatever wasn’t was tossed aside, as were the cultural traditions and historical legacies and religious rituals that had given them meaning and context for hundreds, even thousands, of years, thereby freeing fighters from the limits of the past and lifting the fighting styles themselves out from under the weight of history and tradition.

That makes MMA a truly American art form, like jazz or rock-and-roll: It’s a composite of countless folk traditions smashed together, stripped down and molded into something new. It’s what happens when artistic and athletic disciplines are loosed from their cultural moorings and given room to move, unburdened by the weight of the past and the ghosts, ancestral demands and suffocating expectations of the old world. By its nature, MMA is about cultural multiplicity, creative liberation and the erasing of old lines. Fighters come from every part of the world to make it in the UFC — just like immigrants come to New York City and the United States. The UFC has a Mexican American champion, a Dagestani champion, two champions born in Nigeria, an African American champion, a Croatian American champion and champions from China, Kyrgyzstan, Brazil and Hawaii.

Of course, MMA is ugly, violent and terrifying, but it’s also proof of everything about America that drives Trump and his followers crazy: that cultures are best when they’re blended together; that racial animosity and xenophobia, in addition to being morally indefensible, are counterproductive; that diversity works. Trump’s attacks on cultural pluralism are, by definition, attacks on MMA.

And that’s why we booed.

Still, unless Trump starts making a habit of going to UFC shows, it’s impossible to know whether Saturday’s display was proof of the political passions of mixed martial arts fans in general or just New Yorkers, who live in a state so philosophically, economically and electorally averse to the president that he recently renounced it as his home after 73 years. Either way, the derision probably didn’t matter to a born showman and longtime fight guy like Trump.

The first rule of self-promotion, both in politics and in fighting, is that it doesn’t matter how people react to you as long as they’re reacting. Muhammad Ali knew this. UFC superstar Conor McGregor knows it. And Trump knows it — nearly as well as he knows the second, more sinister, rule, which says that if the facts don’t help you, create your own.

That might explain his tweet the morning after the event: “Walking into Madison Square Garden last night,” he wrote, “was a little bit like walking into a Trump Rally.”

No One Knows Whether Ronda Rousey Still Wants to Fight

Fans hate it when athletes make excuses, but savvy fans know that these excuses can serve a purpose: a fighter who refuses to accept a loss might be gearing up to try to avenge it. Soon after the fight, McGregor posted a defiant treatise on Instagram, concluding with six-word promise: “Nate I will see you again.” Less than two weeks later, a leading M.M.A. site was reporting that a rematch was being arranged; in August, McGregor faced Diaz again, and beat him. He did what he had promised to do.

.. although she gave a moving interview to Ellen DeGeneres, in which she said she contemplated suicide after the loss.

.. Instead of trying to convince herself that being kicked unconscious was no big deal, Rousey essentially confirmed that the experience was shattering, and she betrayed no eagerness to be locked in a cage, once more, with the woman who had shattered her.

.. She had a fledgling acting career and no evident compulsion to avenge herself. Why fight at all, if you don’t need to, and don’t really want to?

.. In November, she gave another interview to Ellen DeGeneres, telling her, “This is definitely one of my last fights.” And a few weeks ago, she was profiled in ESPN The Magazine; she said, “I want to be able to walk away with my head held high.” Some traditionalists believe that fighting for a living requires total commitment, and total confidence; anyone thinking about quitting has, in this view, already given herself permission to quit.

.. We also know, from ESPN, that she has persistent damage to her knee cartilage—unless, that is, she was slyly feeding Nunes some medical misinformation.

.. Rousey is giving fight fans most of what they want: a big fight, even without the customary accompanying big talk. Of course, big talk played a crucial role in transforming Rousey from a skilled M.M.A. champion into a mainstream celebrity. She was the baddest woman on the planet until, suddenly, she wasn’t.

IT’S THE END OF THE U.F.C. AS WE KNOW IT

Last month, one of the sport’s most prominent journalists, Ariel Helwani, was ejected from a U.F.C. event after reporting a story before the company could announce it; White told T.M.Z. that Helwani would never again receive a media credential “as long as I’m here.” (After sports-media outlets erupted in outrage, the company reinstated Helwani.) This approach to media relations seemed reminiscent of a certain Presidential candidate, and perhaps that candidate took note: on Monday, the Donald Trump campaign announced that it had hired Steven Cheung, who happens to be a former publicist for the U.F.C.

.. As White once put it, “It’s none of your fuckin’ business how much these guys are making.”