President Donald Trump’s outbursts against professional athletes protesting racial injustice and the defiant response of NFL teams on Sunday brought a renewed focus on political demonstrations during the national anthem at sports events.

Such acts of protest, often by black athletes and carried out recently by quarterback Colin Kaepernick and others who have knelt for the anthem at NFL games, have a long history in the United States and an equally lengthy tradition of angering mostly white fans, sports officials and politicians.

Here’s a look at some of these controversies:

>> Tommie Smith and John Carlos make their Olympic salute (1968)

During a medal ceremony at the 1968 Summer Olympics in Mexico City, two African-American track athletes made what would become one of the most famous political protests in the history of sports.

The athletes, Tommie Smith and John Carlos, stood on the podium for the national anthem after winning gold and bronze medals and raised their black-gloved fists to the sky in what was widely viewed as a black power salute. Under pressure from the International Olympic Committee, the U.S. Olympic Committee suspended them and sent them home.

On The New York Times’ front page on Oct. 19, 1968, the news was announced: “2 Black Power Advocates Ousted From Olympics.” Some members of the U.S. delegation “hailed it as a gesture of independence and a move in support of a worthy cause,” the article said. “Many others said they were offended and embarrassed. A few were vehemently indignant.”

The swift punishment by Olympic officials served as a warning to others, the article said.

“The action obviously tempered the behavior of Negro American athletes who were involved in victory ceremonies today. In accepting their medals for their one, two, three sweep of the 400-meter run, Lee Evans, Larry James and Ron Freeman wore black berets, but in no way conducted themselves in a manner to incur official wrath.”

>> Vince Matthews and Wayne Collett are barred from the Olympics (1972)

Four years after the 1968 controversy, a new one arose. Track athletes Vince Matthews and Wayne Collett, who were also both black, took the podium in Munich, at a time when officials feared a repeat of the Mexico City gesture.

The Times’ 2010 obituary for Collett said that as the anthem was played, the pair “did not face the flag.”

“They stood casually, hands on hips, their jackets unzipped,” the Times reported. “They chatted and fidgeted.”

The obituary added: “When the anthem ended and they climbed off the stand, the crowd booed. Matthews twirled his medal and Collett gave a black power salute.”

The two men were barred from Olympic competition by the International Olympic Committee, an action that The Times described in an editorial as an “authoritarian decree.”

The editorial continued, “Unquestionably, the slouching, defiant posture of the two black athletes did no credit to either, but the persistence they had shown in training up to perfection pitch demonstrated that they had no lack of the Olympic ‘ethic.’”

>> Fans on Long Island boo college athletes (1973)

Fans at a college track meet at Nassau Coliseum on Long Island went from agitated to furious in January 1973 when at least one athlete lay on the ground during the national anthem.

As the music played, at least one runner from Eastern Michigan University continued to warm up on the floor, the Times reported. Another athlete, “wearing an Adelphi uniform, was also observed reclining on the ground.”

Several fans began shouting, the article said, and after the anthem, “most of the 8,551 spectators joined in the booing.”

The article continued: “Some chanted ‘Throw them out!’ Others shouted racial epithets at the athletes, who were black.”

Later, the Eastern Michigan runner would say: “I was just stretching out, preparing for my race. I didn’t mean any protest, and I’m sorry I caused such a commotion.”

But the booing continued, and some officials threatened to walk off the floor if Eastern Michigan was allowed to compete. The team was disqualified.

The Times quoted Bob Parks, the Eastern Michigan coach, “who is white and wears his hair very closely cropped,” as saying: “I’m as conservative as anyone around. I stand and sing for the anthem. I think the kids should stand, too, and I’m going to give them hell. But why disqualify the whole team?”

Parks said he was surprised by the reaction of the crowd. “At our place, when they play ‘The Star-Spangled Banner’ at basketball games, a lot of the black students don’t stand,” he said. “I guess things are different here.”

>> Madison Square Garden drops the anthem, then reverses its decision (1973)

“Amid growing controversy over whether it should be played at sports events,” a front-page article in the Times on Jan. 16, 1973, reported, “the national anthem has been dropped from the Olympic Invitational track and field meet at Madison Square Garden.”

The Times quoted the meet’s director as saying that playing the anthem was not obligatory because “its purpose and relevance to sports events has never been established.”

A day later, the front page told a different story: “Garden to Hear Anthem at Track Meet, After All.”

The reversal came after the U.S. Olympic Committee was deluged with “irate calls from all over the country,” the Times reported.

>> The NBA suspends Mahmoud Abdul-Rauf (1996)

In March 1996, the National Basketball Association suspended Mahmoud Abdul-Rauf of the Denver Nuggets for his refusal to stand during the national anthem.

Abdul-Rauf, who converted to Islam in 1991, said he did not believe in standing for any nationalistic ideology.

The real problem, according to an editorial in the Times, “was not the wisdom or accuracy of Abdul-Rauf’s view that the flag is ‘a symbol of oppression,’ or that Islamic teachings require that he not stand for the anthem.”

“It was the NBA’s blindness to the fact that trying to force participation in a patriotic exercise undermines democratic values.”

© 2017 The New York Times Company