During the massive Black Lives Matter protests across the country in reaction to the killing of George Floyd, many demonstrators took pains to show their commitment to nonviolence. Yet, according to polls, a substantial proportion of people watching at home perceived the protests as primarily violent. Why do people disagree about this?

Our research, forthcoming in the journal Political Communication, helps explain. Our analysis finds that Americans’ political biases shape their perceptions of whether a protest is peaceful or violent.

Nonviolence is considered critical for protesters to win public support

Some of the most evocative images from the BLM protests showed ordinary people peacefully standing their ground in the face of heavily armed police. Protesters’ effort to signal their restraint reflected decades of research and practice finding that disciplined nonviolence wins more public support than violence.

Ordinary citizens who see nonviolent protests are more likely to support the cause; they are more likely to recoil from groups that resort to violence. Authorities who use force against their nonviolent opponents are likely to provoke a backlash, winning support for their opponents, which isn’t true if protesters are violent.

How we did our research

We conducted survey experiments in 2018 and 2019 with 950 and 981 respondents we found through Amazon’s Mechanical Turk platform. MTurk is fairly representative of the overall population and mirrors the national proportion of liberals and conservatives.

In our study, participants read a fictional news article about a protest, but the details varied randomly along a couple of lines. The tactics mentioned included either holding up placards and shouting slogans, blocking a highway, or throwing rocks and other objects. Further, we randomly assigned the protesting group’s name. The “liberal” group was “Americans Against Racist Policing.” We varied the “conservative” group; in the first round, it was “Americans Against Illegal Immigration” and in the second, “Americans Against All Abortions.”

In other words, respondents read about different combinations of protesting groups and tactics.

All respondents then answered a series of questions on a scale of 1 to 5, including how violent the protest was; how much the respondent agreed with the protest’s goals; whether the protesters should be arrested; and how the respondent felt about protests in general.

Republicans and Democrats perceive protest tactics differently

For “conservative” protests, Democrats and Republicans were fairly even in perceiving the protest tactics as violent or nonviolent. But for “liberal” protests, Republicans were more likely than Democrats to perceive the protesters as violent.

Specifically, Republicans rated the anti-police protesters who were holding placards and who blocked a highway as more violent compared with Democrats.

What’s more, respondents who perceived the protest as violent were also more likely to support arresting the participants — and were less likely to believe that protests are good for democracy.

Why perceptions of protest matter

That matters for activism. Martin Luther King Jr. is often remembered today as a heroic champion of nonviolence. But when he was leading the 1950s and 1960s civil rights movement, many observers saw him as a radical and dangerous agitator — much as some people perceive the Black Lives Matter movement today.

Republicans’ different perceptions of the anti-police protesters may reflect conservative resistance to demands for change in the system, something liberals are less likely to perceive as inherently violent. Or it may grow from conservative perceptions that Black people — who are BLM founders, the movement’s main backers and presumably its potential beneficiaries — as inherently violent, stemming from long-standing U.S. racial bias.

That bias was particularly notable when protesters were depicted as using less disruptive means, like holding up signs. This suggests that even when activists behave in a purposefully nonviolent manner, the simple act of protesting may be seen as sinister.

Politicians who pitch themselves as defenders of “law and order” intuitively understand how this works. By portraying their political enemies as dangerous agitators, they may be able to rouse support for harsh measures against even nonviolent protesters.

During the BLM protests, prominent Republicans like Sen. Tom Cotton (Ark.) and President Trump depicted the movement as threatening, using terms like “thugs,” “mobs” and even “acts of domestic terror.” Conservative media outlets like Fox News disproportionately showed footage of property destruction and theft to support the narrative that the protests were out of control.

This framing may be failing in the United States at the moment, but it has succeeded in the past. And it appears to be working in other parts of the world, as authoritarians seek to gain the upper hand by casting opposition demonstrators as threats to national security.

Scott Radnitz (@SRadnitz) is an associate professor in the Jackson School of International Studies at the University of Washington.

Yuan Hsiao is a doctoral candidate in sociology and a master’s student in statistics at the University of Washington.