Last year, Colin Kaepernick, then the quarterback of the San Francisco 49ers, was heavily criticized for kneeling instead of standing during the national anthem. The protest was on behalf of the Black Lives Matter movement. As Kaepernick put it, “I am not going to stand up to show pride in a flag for a country that oppresses black people and people of color.”

Recently, Kaepernick opted out of his contract with the 49ers. In announcing his free agency, Kaepernick declared that in the upcoming National Football League season he will no longer kneel during the national anthem. However, he has not yet been signed by an NFL team. Some say that’s because his skills are declining. Others argue that quarterback-starved teams are avoiding him because of his protest.

Few disagree that Kaepernick was the target of a great deal of rage — as were the scores of African American high school, college and professional athletes who engaged in similar protests. A 2016 Quinnipiac University Poll found that 54 percent of Americans say they disapprove of these protests. That number hides a divide by race: 74 percent of African Americans say they approve, while 63 percent of whites are opposed. We wondered whether that white opposition is related in part to racial attitudes.

How we did our research

Decades of research on public opinion has found that negative racial attitudes are strongly correlated with white public opinion, particularly when the perceived targets or beneficiaries of a policy change are African Americans (see here, here, and here). We wanted to find out whether white Americans support athletes’ rights to protest the national anthem in the abstract, not just in Kaepernick’s case.

To do this, we fielded a nationally representative online survey in October. We asked 2,000 respondents:

Recently, a number of professional athletes have protested the treatment of African Americans by not standing during the singing of the national anthem. Do you support the right of these athletes to kneel during the singing of the national anthem?

As you can see in the graph below, 34 percent of all Americans say they support these athletes’ rights to kneel during the anthem (30 percent oppose it strongly). But that divided profoundly by race. More than half of blacks were supportive, compared with about 1 in 4 whites.

To explore whether racial attitudes were related to white opposition, we asked respondents to tell us to what extent African Americans fit different negative stereotypes. Specifically, we asked whether respondents thought African Americans were lazy (vs. hard-working), unintelligent (vs. intelligent) and violent (vs. peaceful). We also asked people in our survey to rate whites on these same traits. We then looked at the difference between how white respondents rated whites on these scales to how they rated African Americans. When they rated African Americans as more lazy, unintelligent and violent than they rated whites, we took this as evidence of racial stereotyping.

We also asked questions that examined partisanship, ideological attachments, patriotism, gender, age and education. This allows us to see whether opposition to the protests is related to racial stereotypes even after controlling for other factors.

The big role of racial bias

Racial attitudes had a notable relationship to white opposition to athletes’ protests. The graph below shows precisely how strong the relationship is between holding negative stereotypes of blacks and strong opposition to the protests. Even after we account for all the factors we listed above, we still find that whites who hold the most negative stereotypes about blacks are about 25 points more likely to strongly oppose athletes kneeling during the anthem than whites who have positive views of blacks.

In short, race appears to matter — a lot — in understanding white opposition to these protests.

Tatishe M. Nteta is an associate professor in the department of political science at the University of Massachusetts at Amherst.

Brian Schaffner is professor of political science at the University of Massachusetts at Amherst.

Matthew C. MacWilliams is a visiting research associate at the University of Massachusetts at Amherst and is writing a book on authoritarianism for Penguin Press.