In the early 1990s, John McCain, a former boxer and lifelong fan of the sport, watched an Ultimate Fighting Championship bout for the first time. He hated it. Mixed martial arts, he told Larry King, “appeals to the lowest common denominator in our society.” Soon after, he wrote to every governor in the country, asking them to ban what he described as “human cockfighting.”

Over the past 23 years, however, the UFC has evolved from a no-holds-barred blood sport into an international sensation, landing deals with Fox Sports and Reebok. In July, Lorenzo Fertitta and his brother Frank sold the UFC to a group led by talent agency WME-IMG for $4 billion—the biggest deal in sports history. On November 12, the UFC will hold its first event in the state of New York, at Madison Square Garden, America’s most famous arena. Once a pariah, the UFC is now on par with NASCAR and the PGA, and within striking distance of the “big four” pro sports leagues: the NFL, NBA, MLB, and NHL. To hear Lorenzo Fertitta tell it, McCain actually saved the sport. There are now official weight classes and rounds, and a number of less palatable moves—hair-pulling, head-butting, groin-hitting—have been banned. “I have to give him credit,” Fertitta told Fox. “Without him doing what he did back in the ’90s to force regulation, this sport would be dead.”

Yet the UFC has refused to give up one dirty move in its path to mainstream success: union bashing. For years, the Culinary Workers Union has tried unsuccessfully to organize workers at Nevada casinos owned by the Fertitta brothers, who have fought the unionization drive. To apply pressure, the culinary workers convinced the New York state assembly to ban the UFC from staging bouts, even after every other state in the country had legalized MMA. Dana White, the UFC president with the brash instincts of Don King, called out the culinary workers in the manner of a trash-talking prizefighter. “They’re dirty, dirty, dirty,” he said in 2013. The UFC’s path to victory in New York was cleared only last year, after Sheldon Silver, the speaker of the New York assembly and a leading ally of the culinary workers, was arrested on corruption charges.

The UFC’s success has also renewed calls for a players union, akin to those in other major sports. Fighters take huge risks every time they step into the ring—despite increased safety, MMA is still a punishing sport. But unlike players in the big four, UFC fighters have no pensions, comprehensive health care, or disability benefits, and no recourse if the UFC decides to discipline them for bad behavior or even simple disloyalty. UFC fighters get only 15 percent of league revenues, compared to half for players in the NFL, NBA, MLB, and NHL. The unions for the big four, all founded between 1954 and 1967, haven’t diminished the growth of those leagues: Last year they brought in a combined $32 billion in revenues.

Team sports, of course, recognize that it takes more than just a flashy superstar to achieve success. And even individual sports like golf and tennis, which don’t have unions, attempt to operate as meritocracies, with transparent ranking systems and pay structures for every event. Yet the UFC is still run as a feudal society, with fighters at the mercy of management. White, who is personally worth half a billion dollars, likes to make a show of handing out “locker-room” bonuses to reward fighters after an entertaining match. And he dismisses anyone who complains about the UFC’s low pay and lack of benefits as a crybaby. “We’re in this fucking society now where everybody should win a trophy,” he has said. “No, everyone doesn’t win a fucking trophy.”

The UFC has fought tooth and nail to prevent fighters from unionizing. Last year, after the Teamsters and the Culinary Workers announced plans to organize fighters, the UFC sent emails to its fighters calling the union organizers “shameful and pathetic.” The UFC also warned fighters—inaccurately—that if they unionized they would lose control of contract negotiations and be forced to be “completely submissive” to union bosses.

But the UFC’s $4 billion sale this summer has only increased calls for fighters to band together. “These guys have lined their pockets with our blood,” UFC heavyweight Mark Hunt said in July. And in August, sports superagent Jeff Borris—best known for representing baseball stars like Rickey Henderson and Barry Bonds—announced an effort to form a Professional Fighters Association, the most robust plan to organize UFC fighters to date.

“It’s embarrassing,” Borris says of the UFC’s treatment of fighters. “They are at the bottom of the barrel. Their contracts are laughable.” Borris counts himself a fan of the sport. “I’ve watched the fights since the old days—I like watching it,” he says. “But the fighters are the ones that drive the business, and they are deserving of more than mere bread crumbs.”

Bread crumbs, however, are exactly what the UFC believes its fighters deserve. Dana White, who lauded Donald Trump as “a fighter” at the Republican convention, sees the world in Trumpian terms. To White, there are two kinds of fighters: those who earn one of his “locker-room” bonuses with a violent knockout, and the losers who wind up unconscious. “The guys who are complaining about this are the guys that don’t matter,” he has said. “The guys who make it exciting—the guys who rise to the top—are the guys who deserve the money. Let’s not forget, we live in fucking America, the land of opportunity.”