Colin Kaepernick greets fans after a Jan. 1 game in Santa Clara, Calif. (Tony Avelar/AP)

A self-appointed social critic recently warned against fostering “a monoculture that maintains its hold by shaming dissenters into silence.” The NFL’s issue with Colin Kaepernick is not about belief, but conformity to its monoculture. Owners don’t really care much what Kaepernick believes, what his cause is. They care that he is a disrupter-dissenter who refuses to play the stock character role assigned to him and might threaten a bottom line. As a result, they have blacklisted him — there is no other term for it — and in doing so have unintentionally underscored his message about pervasive injustice for blacks. This larger wrong is beginning to overtake any original insult or disrespect he may have committed.

Americans don’t like gag rules and pressured silences and enforced obedience of any stripe and usually end up kicking back like mules. If the owners doubt this reflex, they should consider that the above quote is not from some progressive-subversive lefty. It’s from James Damore’s memo about Google’s “Ideological Echo Chamber,” which got him fired for questioning the company’s corporate gender diversity effort. You don’t have to agree with Kaepernick taking a knee during the anthem last season — or Damore’s reasoning and language — to be offended by the fact that they are out of jobs for speaking their well-intentioned minds.

There are people in the NFL whose handshakes ought to come with bottles of antibiotic soap, but Kaepernick remains unsigned despite the fact that he is clearly among today’s top 50 quarterbacks and has played in a Super Bowl. This is “revenge in excess of the injury,” to borrow a phrase from W.H Auden. Free speech is not guaranteed in the workplace, of course, and this is not to defend every one of Kaepernick’s actions, such as wearing socks emblazoned with pigs. But what’s also not guaranteed is that the NFL’s audience won’t turn against it for needlessly making a martyr of Kaepernick and serve it up a heaping plate of backlash.

It will be interesting in the extreme to see how much NFL owners care about offending large swaths of their black audience and their own players. African Americans make up 15 percent of the league’s TV viewers and 70 percent of its players. The Atlanta chapter of the NAACP has called for a boycott of the NFL until Kaepernick is signed by a team. A half-dozen black Southern pastors, with a network of peers all over the country, have asked churches to tune out the NFL. They made a video titled “I’m Blacking You Out” that they say has gotten 7 million views and six-figure shares on Facebook. New York City police officers rallied in support of Kaepernick last weekend. Filmmaker Spike Lee was scheduled to join a multi-group protest in front of the NFL’s Park Avenue offices Wednesday.

In this Aug. 12, 2017, file photo, activist Najee Ali gestures during a small protest outside of the Los Angeles Memorial Coliseum. (Jae C. Hong/AP)

These are not people on the fringe. These are clergy, college presidents, lawyers and law officers. And Hank Aaron, who spoke in defense of Kaepernick to broadcaster Roland Martin.

“What we’re seeing and hearing could easily — right now — could easily gain greater momentum and cost the NFL a segment of its fan base,” said Rob Ruck, a sports historian at the University of Pittsburgh and author of “Raceball: How the Major Leagues Colonized the Black and Latin Game.”

Atlanta NAACP vice president Gerald Griggs is a civil rights attorney — and the son of a Vietnam veteran — who played youth football and has watched the NFL since he was 4 years old. But he is calling for a boycott against NFL teams because “the only language they speak is revenue.” The pro-Kaepernick movement is not a small minority but a growing coalition, he said, and he predicts an increase in involvement by NFL players, such as the dozen Cleveland Browns who took a knee this weekend.

“There has been momentum building for something of an economic disturbance,” Griggs said. “. . . We can see clearly where the mood of the nation is, and I don’t think NFL owners want to be on the other side of the mood of the nation. It’s a long season, and steam will build.”

Pellom McDaniels is a curator at Emory University’s archives and a professor of African American Studies, as well as a former NFL defensive end who played from 1993 to 2000 with the Kansas City Chiefs and Atlanta Falcons. He sees the Kaepernick controversy in the larger continuum of pro football’s checkered civil rights history, which he describes as “blips in a narrative in which segregation was the norm.”

There was Fritz Pollard in the 1920s, the long gap before the 1946 signings of players such as Marion Motley and Kenny Washington and then the wholesale restructuring forced by Lamar Hunt, who drafted AFL players from historically black colleges and universities, and Al Davis, who fought not just for blacks but also Latinos. They were owners who began as outsiders growing their teams on the cultural margins and “pushed back against the status quo,” McDaniels said.

Retired New York City Police Officer Frank Serpico, center, stands with other members of law enforcement during a rally to show support for Colin Kaepernick on Saturday. (Mary Altaffer/AP)

Where are those owners today? “I don’t think those owners exist anymore,” McDaniels said.

The enormous commercial success of the league in the intervening years, McDaniels argued, bred brand conservatism — and short-circuited conversations about racial issues inside of the league. “With the revenue generated, all of a sudden it’s a conversation we don’t have to have, because there is a market,” he said.

But the market is changing. You can feel it, like the ions in approaching weather. Generational interest is flagging because of everything from egaming to concussions, and the NFL from a practical standpoint can ill afford to lose any segment of its core audience. As The Washington Post just reported, at the youth level, from which high schools draw their players, there was a 30 percent drop in participation between 2008 and 2013, according to the Sports & Fitness Industry Association. Meanwhile, NFL ownership has calcified into an unimaginative feudal society with fixed obligations, in which they think that an experiment is fooling with the food at the concessions or with rule changes. The average age of owners is over 70.

The NFL began shunning Kaepernick in a different environment six months ago. Then came Charlottesville. The league badly needs a smart leader, a new Lamar Hunt, an owner who doesn’t have to feel the forehead of the fans to step forward and say, “Ostracism is not what we do. We applaud our players for taking positions on social issues, and we, too, want to live in a more just and equitable society, and that’s the broadest base to which we appeal.”

It needs a leader with a view not just of what should be done in this particular moment but what the league must do more broadly about creeping audience disaffection. Instead it keeps kicking cans down the road. “It’s confounding,” McDaniels said.

To pastor Debleaire Snell of Huntsville, Ala., who helped launch the “I’m Blacking You Out” movement last week, the league’s collective refusal so much as to invite Kaepernick to a training camp “reeks of corporate arrogance that says essentially, ‘Even though this is a valuable cause to a large portion of fans, we still have the expectation they will be there on opening day.’ And that’s a gross miscalculation.”

Since launching the movement, he has heard from pastors in Dallas, Nashville and Cleveland who have offered to join in. “People of conscience, people who are thoughtful, people around the water cooler, are having this conversation,” he said. “We are just putting out the open call.”

By attempting to shut Kaepernick’s mouth for fear of offending customers, the NFL has only opened more mouths. And that may cost it greatly in the end.