Floyd Mayweather, at left in striped sweatshirt, and Conor McGregor, seated, traded racially tinged taunts at promotional tour stops last month in Brooklyn and other cities. (Noah K. Murray/USA Today Sports)

For all the novelty of their fight, Conor McGregor and Floyd Mayweather Jr. have relied on boxing’s most durable means of promotion. Through words and behavior, they have concocted a racial rivalry in a climate ripe for exploiting it.

In promotional stops in Los Angeles and Toronto, McGregor said to Mayweather, “Dance for me, boy.” In a subsequent tour stop in Brooklyn, following criticism of those remarks, McGregor explained he couldn’t be racist because he was “half-black from the belly button down.” He then thrust his pelvis as a gesture “for my beautiful black female fans.” Mayweather has since stated many people believe McGregor is racist and dedicated the fight to “all the blacks around the world.”

In a country still wracked by the recent horror of Charlottesville, Mayweather and McGregor will fight Saturday night in Las Vegas in perhaps the richest and most outlandish boxing match in recent history. Mayweather, a 40-year-old with a 49-0 career record and regarded as one of the greatest tacticians in the sport’s history, expects to earn more than $200 million. McGregor, 29, an incendiary mixed martial arts champion who hasn’t strictly boxed since he trained as a youth at the Crumlin Boxing Club in his native Dublin, expects to clear $100 million.

The racial undertones emanating from the promotion of Mayweather-McGregor echo the sport’s history of using racial conflict — genuine or otherwise — as a selling point. McGregor may not be cast as a traditional Great White Hope, an oft-used trope for more than 100 years of fights. But playing up a black-white divide has been a hallmark of boxing promotion since the early 20th century, and Mayweather and McGregor have proved the durability of the tactic.

“We have a very polarized and very conflicted racial environment right now,” said Jeffrey T. Sammons, a history professor at New York University and the author of “Beyond The Ring: The Role of Boxing in American Society.” “And I’m sure McGregor probably has a lot of white supremacists that are rooting for him.”

From Jack Johnson to Muhammad Ali, fighters have used boxing as a vehicle for social change, but more often, race has been used as a marketing ploy, an appeal to one set of base urges in a sport built on them. Critics see McGregor and Mayweather contriving racial animosity to help sell a fight as opposed to pursuing a greater cause.

“The thing about Jack Johnson and Joe Louis and Muhammad Ali is they transcended their sport in numerous ways,” Sammons said. “But this comes out of nowhere. I’ve never heard Floyd Mayweather commenting on race before, taking any kind of social position. He’s just been a boxer. He’s never transcended his sport. So this rings hollow as something that has any kind of basis in real feeling.”

“It’s distasteful what’s going on,” said former heavyweight Gerry Cooney, now a host on Sirius XM radio. “They’re misusing words, and they’re using it to promote it.”

Boxer Floyd Mayweather and UFC fighter Conor McGregor appear in Las Vegas ahead of their big fight on Aug. 26.

Cooney took part in one of the most racially charged promotions in recent memory. When Cooney fought Larry Holmes for the heavyweight title in 1982, 22 years had passed since the last white heavyweight champion. Don King labeled Cooney as the latest Great White Hope, and Holmes stated he got the title shot only because he was white. Cooney appeared on the cover of Time magazine. Each fighter’s purse cleared $8 million, and Holmes questioned whether Cooney’s pay would have matched him had he been black.

White supremacist groups threatened to shoot Holmes the night of the fight. Black rights groups countered with vows to retaliate if anything happened to Holmes. On the night they walked into an outdoor ring in Las Vegas, police snipers stood on roofs to protect the fighters.

“It’s a selling point,” Cooney said. “There’s a lot of ignorant people in the world. So they want to hear it. They want something to put on their back and stand up for. It’s just a small group of those people. But it sells tickets.”

The setup for Saturday night’s fight — a black boxing champion, seeking a massive purse, finding a white challenger with no experience at the higher rungs of the sport — echoes the plot screenwriter Ron Shelton imagined for the 1996 film “The Great White Hype.” Shelton, an ardent student and an avid connoisseur of boxing who leaned on history to create his art, can see repetition of his art in life.

“If this was a black UFC champion and Mayweather,” Shelton said, “I don’t think they’d sell a ticket.”

Shelton did not draw on Cooney-Holmes specifically for his script — he viewed Cooney’s performance as worthier than many white challengers — and his film differs in detail from Mayweather-McGregor. McGregor is a world famous mixed martial arts fighter who has never boxed. The fictional white challenger, played by Peter Berg, was the unknown frontman for a heavy metal band and had defeated the champion (Damon Wayans) as an amateur. Wayans’s character loafs through training, and Berg’s undergoes a stirring transformation — and then the champion knocks out the white challenger in 27 seconds.

Shelton doesn’t see Saturday’s fight being much more competitive.

“This makes no sense that they’re selling this many tickets,” Shelton said. “Mayweather is one of the greatest fighters of all time. The other guy is 0 for 0 … There’s a long tradition of being your people’s champion and putting down the other. It’s all about money.”

The boxing cognoscenti has a similarly bleak competitive outlook. And yet, promotion along racial lines works only if fans buy in, subconsciously or otherwise. The public clearly believes McGregor can win despite his inexperience: The odds for him to win have fallen from 11 to 1 to 3¾ to 1.

The roots of race playing a role in boxing promotion are far darker. After Jack Johnson won the heavyweight title in 1908, in the middle of the Jim Crow era, white America revolted. Riots filled city streets. Laws were passed that prevented transport of film of Johnson’s victory across state lines. The novelist Jack London called on a “Great White Hope” to beat Johnson and restore natural order.

“I feel obligated to the sporting public at least to make an effort to reclaim the heavyweight championship for the white race,” said James J. Jeffries, a leading white contender. “I should step into the ring to demonstrate that a white man is king of them all.”

White America erupted after Jack Johnson, shown in an undated photo, won the heavyweight title in 1908. (Associated Press)

Promoters gave black fighters nicknames meant to stoke exotic otherness, such as Joe Louis, above, known as “The Brown Bomber.” (UPI/Bettmann)

Johnson rebelled against retrograde social norms, making no attempt to act humbly or hide his carousing with white women. He was arrested under the Mann Act, which made it a crime to take women across state lines for “prostitution or debauchery, or for any other immoral purpose.”

Promoters gave black fighters nicknames meant to stoke exotic otherness. Before Joe Louis was called “The Brown Bomber,” posters referred to Sam Langford as “The Boston Tar Baby” and Harry Willis as “The Black Panther.” Willis and Langford, the best black fighters of their time, were not allowed title shots against white champions.

Boxing always has been an immigrant sport, and in big cities, fans would clamor for fighters who came from neighborhoods constructed along ethic lines. In radio ads before some fights, promoters would spell Billy Conn’s last name to ensure fans knew “he’s the Irish guy, not the Jewish guy,” Shelton said.

In the 1960s and ’70s, a period with a dearth of white heavyweight contenders, fighters and promoters still managed to use race to market matches. Ali mastered the tactic of turning black opponents into symbols of whiteness. He pummeled Floyd Patterson and Ernie Terrell for calling him Cassius Clay after he changed his name. He also called Joe Frazier “Uncle Tom” and “Gorilla,” which was deeply hurtful for Frazier.

“Those blacks became stand-ins for the authority or the establishment or the so-called ‘man,’ ” Sammons said. “When there weren’t real White Hopes, black people became white folks based on what was perceived to be their political positions.”

Race still works to arouse interest in boxing, and recently, Cooney learned how dubious it can be. About three years ago, Cooney’s wife sent away to learn his ancestry. The results stunned him: It turned out Cooney’s grandfather’s mother was African American. The Great White Hope, all along, had black ancestry.

“So,” Cooney said, “it was a lie.”