When President Trump inserted himself into the debate over NFL players' symbolic protests during the national anthem, he very likely believed that he was amplifying the righteous instincts of a "silent majority" of Americans. And he's probably not wrong. Recent polls suggest that while people don't support the idea of firing athletes for these weekly demonstrations, they are turned off by them.

This is hardly surprising. The white American mainstream, to the extent that such a thing may still be said to exist, has felt irritated or threatened by minority protest movements from the civil rights era to the present day. You can see it very clearly in contemporaneous reactions to these protests.

My children's impression of Martin Luther King is the one that's been inculcated in them by elementary school teachers: courageous hero whose literal monumental status is not unlike that of the country's founders. Later in their educational careers they will learn just how besieged he was, personally and politically, at the end of his life. On MLK Day this year, historian Joshua Zeitz noted in Politico Magazine: "On the eve of his death on April 4, 1968, he was more controversial and less popular than he had been at any time in his public career. In a Gallup poll conducted in 1963, 41 percent of respondents rated him favorably, and 37 percent negatively. In 1967, just 32 percent gave him a favorable rating, whereas 63 percent viewed him negatively."

One year after King's assassination, during an awards ceremony at the Summer Olympics in Mexico City, the sprinters Tommie Smith and John Carlos raised their fists in a Black Power-esque salute to highlight poverty in America's inner-cities. They were met with this reaction in Time magazine: [T]wo disaffected black athletes from the U.S. put on a public display of petulance that sparked one of the most unpleasant controversies in Olympic history and turned the high drama of the games into theater of the absurd.” When they returned home, they were suspended from the U.S. track team and received death threats.

A few years later, America met an unknown actress named Sacheen Littlefeather, who was dispatched by Marlon Brando to decline his Academy Award for best actor in protest of Hollywood's (and the country's) maltreatment of Native Americans. One could easily hear the angry-white-guy ethos of Donald Trump in John Wayne's response to Brando's stunt: "If he had something to say, he should have appeared that night and stated his views instead of taking some little unknown girl and dressing her up in an Indian outfit."

Recall, more recently, last year's #OscarsSoWhite boycott. Black filmmakers and actors called for Americans to "tune out" the Academy Awards broadcast because of the industry's persistent marginalization of minority talent. Only 23 percent of Americans supported the boycott, according to a Reuters/Ipsos poll. And when some black entertainers like Ice Cube balked at the protest, he perhaps inadvertently provided cover to those who disdained these (to borrow a put-down from our latest drama) "ungrateful black multi millionaires [sic]."

Tellingly, many whites are no more receptive to protests about the plight of minorities even when they are lodged by a white man. For instance, Bruce Springsteen began performing the song “American Skin (41 Shots),” a brooding, sensitive-to-both-sides chamber piece about the shooting of an unarmed African immigrant by four New York City Police, at concerts in 2000:

Then-Mayor Rudy Giuliani and the city's police commissioner howled in indignation. The head of the Patrolmen's Benevolent Association urged the city's police officers to boycott Springsteen's concerts. The chief of police went so far as to withdraw Springsteen's police escort for a night.

In short, when confronted by protest from someone even higher in the social hierarchy, these powerful white men whined, called for boycotts, and retreated, however briefly, to their safe spaces. As with the Blue Lives Matter counterprotest movement, the instinctual response to any assertion of a sub-American identity is one of irritation, scorn, and outright fear.

Over time, as with MLK's legacy, some social movements eventually are vindicated. The country hears grievances. Controversy ensues. Clashes occur. The culture changes. Controversy fades. Springsteen's "American Skin" took on a sad new relevance, in 2012, after the killing of Trayvon Martin by a self-appointed neighborhood watchmen. He's been playing the song off and on ever since, and, as police shootings of unarmed minorities grab headlines, no one is offended by it anymore.

The lesson to would-be protesters is double-edged: Just because they don't like you doesn't mean you're wrong — but neither does it mean, in every case, that anything will change.