Editor's Note: (Peniel Joseph is the Barbara Jordan Chair in Ethics and Political Values and the founding director of the Center for the Study of Race and Democracy at the LBJ School of Public Affairs at the University of Texas at Austin, where he is also a professor of history. He is the author of several books, most recently "Stokely: A Life." The views expressed here are his.)
(CNN) The President has excoriated football players who have joined a protest movement by former 49ers quarterback Colin Kaepernick as unpatriotic. But the President is overlooking history -- which shows athletes now lauded as heroes, like Jackie Robinson and Muhammad Ali, raising their voices (or taking a seat) in protests similar to Kaepernick's.
Whether they are taking a knee to protest police treatment of black Americans or to express solidarity with their teammates' decision to do so, the hundreds of NFL players now under scrutiny represent a long-standing American tradition of social justice activism among athletes, which is itself an embodiment of patriotism.
Black athletes, in particular, have always occupied a dual role that straddles sport and politics, the result of pursuing athletic excellence in a nation which, for much of its existence, practiced racial segregation.
Throughout the course of the 20th century, sports and politics have been inextricably linked. Politics have also always shaped the business of sports in America, with racial breakthroughs being based as much on financial profit as moral good. The desegregation of professional and collegiate athletics, for instance, fueled the rise of a multi-billion-dollar global sports industry.
The President's charge that kneeling to protest racial injustice is somehow un-American speaks to national confusion about the beating heart of our democracy, which is founded on the fundamental right to protest for our rights.
Jackie Robinson, rightfully celebrated for showing enormous grace under pressure while breaking baseball's color line, refused to stand for the National Anthem after his playing days.
As he described in his 1972 autobiography, Robinson -- like contemporary NFL players -- was protesting against institutional racism. He was expressing his feelings of alienation from America's system of racial apartheid.
Robinson's pugnacious brand of civil rights activism set the stage for succeeding generations of black athletes. Eleven-time NBA champion Bill Russell emerged as one of the most outspoken civil rights advocates of the 1960s, at a time when the city he played in, Boston, represented one of the most racially segregated cities in the North.
Muhammad Ali, crowned heavyweight champion in 1964 after defeating Sonny Liston in perhaps the biggest upset in boxing history, represented for many an unforgivable brand of blackness during the 1960s. The formerly named Cassius Clay announced his membership in the Nation of Islam immediately after winning the title. For a short time, he brandished his friendship with Malcolm X as a political sword and made no bones about his dedication to the Nation of Islam's political activism. The two men toured the United Nations and walked the streets of Harlem trailed by reporters and photographers.
Ali's refusal to serve in Vietnam in 1967 made him one of the most recognizable figures in the world, the boxing champ who defied an empire to preserve his own soul. Ali's dissent from the war, even as it was based on his religious and philosophical principles, also hinged on a public recognition of systemic racism in America
Alongside of the Rev. Martin Luther King Jr., Ali helped link the civil rights and peace movements together in mutually reinforcing opposition against war, violence and racism.
Although now celebrated as an icon, complete with what was practically an unofficial three-day state funeral, attended by former presidents, after his death last summer, Ali was vilified throughout the late 1960s, stripped of his boxing license and heavyweight title for four years, and almost driven out of sport, only to reclaim his financial and international standing against all odds.
By the summer of 1968, black athletes were becoming international symbols of protest against racial injustice, most famously embodied by sprinters Tommie Smith and John Carlos, who held up black gloved fists on the podium at the Mexico City Olympics. Smith and Carlos were the most visible athletes who joined efforts organized by scholar-activist Harry Edward to boycott the Olympic Games. Plans for the initial boycott evolved into protests against institutional racism that, in the aftermath of Mexico City, became global in scope.
This rich tradition of athletes being voices of protest against racism transcends patriotic symbols of American exceptionalism, whether represented by the flag or by the National Anthem. Civil rights protests, Black Power radicals, athletes and other social justice activists have openly questioned whether America could really be an exceptional nation when its black citizens were subject to such mistreatment.
It's a tradition that's living in the present. In the wake of the Black Lives Matter movement, basketball superstars -- most notably LeBron James, Chris Paul, Dwayne Wade and Carmelo Anthony -- have been outspoken critics of racial injustice in the criminal justice system.
A range of NFL players, including Anquan Boldin and Malcolm Jenkins, have also gone to Congress to lobby on behalf of criminal justice reform. Through fundraisers, philanthropy, social media, and interviews a wide array of black athletes and white allies have stood up -- and taken the knee -- on behalf of social justice.
President Trump has attacked black athletes, using a series of racially coded dog whistles that have grown coarser over time. For instance, he contrasts black football players' actions with the words of NASCAR team owners who denounced protesting the anthem. President Trump tweeted that he was "proud of NASCAR and its supporters and fans" -- even though one of its most famous drivers, Dale Earnhardt Jr., tweeted "All Americans R granted rights 2 peaceful protests."
Because NASCAR itself has remained silent and because NASCAR's fan base is so largely white and male, many see the President's tweet as a way of making a statement about race, without having to be more explicit.
No single group of Americans owns the flag or has the right to decide the parameters of individual or collective protest against injustice.
Suggestions that black protesters who kneel during the anthem are un-American or should lose their jobs is politically and morally reprehensible. More importantly, those suggestions set up a new form of racial intolerance, where once again, black protest is deemed both unworthy of thoughtful consideration and patently un-American.
Above all, black American athletes are citizens, fathers, brothers, husbands and sons who have a right and responsibility to continue a long struggle for dignity exemplified by Jackie Robinson, Bill Russell and many others.
Donald Trump's assault on the character of black football players ignores history by sidelining the very reason they are protesting.
More troublingly, it reveals once again, that we have an occupant in the White House unable to recognize that America's true greatness lies in its enormous capacity for social transformation; the ability of visionary leaders and ordinary citizens to right ancient wrongs, admit grievous mistakes and, by correcting historic injustices, choose love over hate.