Following San Francisco 49ers quarterback Colin Kaepernick’s protests of racial oppression and inequality by refusing to stand at attention during the national anthem, many other National Football League (NFL) players have joined in similar protests during the first two weeks of the regular season.

Kaepernick, who is biracial and was adopted and raised by his white parents, began his protest in August during preseason games. He explained his actions by stating, “I am not going to stand up to show pride in a flag for a country that oppresses black people and people of color. To me, this is bigger than football and it would be selfish on my part to look the other way. There are bodies in the street and people getting paid leave and getting away with murder.”

There were widespread denunciations by police organizations and right-wing politicians and media pundits, denouncing his actions as unpatriotic, if not treasonous. There were a few cases of supposed “fans” burning his jersey. These efforts failed to stifle the display of political and social opposition, as support for Kaepernick among NFL players, other athletes, and the public has instead increased.

Many players throughout the NFL’s first two weeks of the season have engaged in similar protests and Kaepernick’s jersey has now become the NFL’s number one seller, even though this season Kaepernick, a starting Super Bowl quarterback in 2012, is a back-up this year.

In the regular season’s first two games Kaepernick has continued to kneel during the anthem and has been joined by teammate Eric Reid, while teammates Antoine Bethea, Rashard Robinson, Eli Harold and Jaquiski Tartt have stood with raised fists.

Miami Dolphins Arian Foster, Kenny Stills and Michael Thomas have taken a knee during the anthem in their first two games. Foster, who last year publicly described himself as an atheist, said the main purpose of their demonstration is to create a healthy dialogue on issues of systemic racism such as education, the prison system and police brutality toward minorities. “If somebody is telling you they don’t feel like they’re free, why wouldn’t you listen to them?” he asked.

Jason McCourty and Jurrell Casey of the Tennessee Titans kissed their hands and raised their fists after the national anthem before this week’s game in Detroit. Both players had raised their fists during the anthem in Week 1. Casey explained their gesture was “a small symbol showing we are looking for equal opportunity in this world, and we just need justice for all the things that’s going on around here.”

Brandon Marshall of the Denver Broncos took a knee during the anthem for the second week in a row, despite having lost two commercial endorsements for his first protest. “I’m not against the military. I’m not against the police or America,” Marshall said, according to the Denver Post, “I’m against social injustice. Kaep, he’s using his platform how he wants to use it, to reach the masses. We have freedom of speech. But then we use our platform, and we get bashed for it. It’s almost like they want us to only go with the grain. And once we go against the grain, it’s an issue.”

Other players who have continued to raise fists during the anthem include Robert Quinn of the Los Angeles Rams, and San Diego Chargers Joe Barksdale and Chris Hairston. A number of other players, including Martellius Bennet and Devin McCourty of the New England Patriots, Jeremy Lane of the Seattle Seahawks, and Marcus Peters of the Kansas City Chiefs engaged in similar anthem protests before their games in Week 1.

All of these players are African-Americans in a league whose players are 70 percent black.

Anthem protests have also occurred at various high school games throughout the country. In Seattle at last Friday’s game players and coaches from Garfield High knelt in unison before their game against West High, with several West High players also joining. Garfield Coach Joey Thomas said his players decided to kneel after talking among themselves about Kaepernick and social injustice. “How are you killing these African American males on camera and we can’t even get a day in court?” he asked.

Many other high school players throughout the country have engaged in similar protests and players in New Jersey, Massachusetts and Alabama are facing suspensions for their symbolic protests.

This issue has been absent during this season’s college football games only because in most college games the anthem is played before the teams take the field.

Outside of football, Megan Rapinoe, a member of the US women’s soccer national team, has been kneeling during the anthem as a gesture in solidarity with Kaepernick and others protesting social inequalities. “We need to look at all the things the flag and the anthem represent and all the things it means, and is it protecting everybody? There are people who don’t feel as protected as I do every day. I know it’s a time-honored tradition. Especially in a sports environment, it’s something the country is very passionate about, but there is a bigger conversation here that is more important than sports.”

Rapinoe, longtime advocate for LGBT rights, is also one of five players named in an equal-pay complaint filed against US Soccer and was a vocal critic of the artificial turf used during the 2015 World Cup.

As the WSWS has frequently explained, the fundamental source of police violence is not racism but class oppression. Police kill many more whites than blacks, and many of the police doing the killing are themselves recruited from racial minorities.

To be sure, a disproportionate number of victims of police killing are black, and racism is certainly a factor. What virtually all victims of police violence have in common is their social class, as almost all are members of the working class, particularly the poorest and most oppressed sections of the working class.

Kaepernick and other NFL players who have been protesting police violence have demonstrated personal courage and have shocked the authorities, including both the billionaire owners of the football teams and their highly paid media partners.

For the time being, taken aback by the scale of the protests and the open support for the players from many fans, the NFL has hesitated to retaliate. For how long this will persist is unclear.

Fox and CBS, which have billion-dollar contracts to broadcast NFL games on Sundays, and NBC, which broadcasts Sunday Night Football, seem to have adopted a policy of ignoring the protests, giving virtually no attention to them this weekend, although more athletes were involved than in Week 1 of the season.

The athletes engaged in these protests have a limited and largely racial perspective on police violence. But their outrage over police violence is entirely healthy and reflects deeper currents stirring within the American population.