The #BlackLivesMatter (BLM) movement has been making headlines, but not necessarily friends. When BLM protesters stormed the stage at rallies for Democratic Presidential candidate Bernie Sanders in August 2015, commenters lamented that protesters were “pissing on their best friend.” African-American comedian Larry Wilmore opined, “Black lives matter, but black manners matter too.” Going after progressive elected officials is, quite simply, “bad politics.”

This kind of commentary has been a consistent presence since BLM first mobilized in response to the police killing of Michael Brown, an unarmed African American teenager, in August 2014. In the San Francisco Bay Area, protesters have blocked highways and public transit and even burst into Sunday brunches to convey their message. The responses have not always been favorable, even from those who claim to support the movement’s goals. As one observer claimed, “aggressive and disruptive tactics…seem unlikely to elicit a sympathetic hearing…and thereby seem unlikely to bring about meaningful change.” When black students of the University of California, Berkeley used disrupted tactics in an affluent shopping district, a self-declared backer suggested, “Cal’s political science department should teach some classes on how to be effective in making political change… It is more effective to try to gain support from people who are sympathetic to your cause than to harass them.”

BLM protesters might not need a political science course, though, because they’re already getting a key point right. Disruption isn’t just an effective tactic; it’s often the only effective tactic for those who have been excluded or marginalized in the institutional political process. Armchair social movement critics, on the other hand, might be better served by a course on movement impacts. Decades of research confirm that confrontation and contention are often a crucial ingredient in political change.

The often explicit comparison point for BLM has, unsurprisingly, been the Civil Rights Movement (CRM) of the 1960s. For some, the CRM speaks to the power of disciplined organization, careful self-presentation (marchers often wore their Sunday best!), and alliance-building with public officials. But even if today the CRM looks like a model of respectability, the histrionic response to the movement’s actions shows that Southern authorities saw the movement as an immensely disruptive force, threatening the established order and indeed the way of life of the old Confederacy.

Indeed, disruptive tactics drove the movement forward across its entire lifetime. As Douglas McAdam has shown, using an extensive catalog of Civil Rights Movement events, the “pace of the black insurgency” quickened whenever the movement adopted new aggressive tactics—from lunch-counter sit-ins to bus boycotts.^[1] Although lunch counter sit-ins were more frequent in cities with vicious segregation and smaller black populations, cities jolted by such protests were nonetheless far more likely to desegregate.^[2]

Such tactics—the historical precedent to shutting down shopping in a liberal neighborhood today— worked even though they almost certainly alienated potential allies. Bus-boycotts hurt blue-collar drivers, anti-war protests at places like Berkeley were almost certainly frustrating to students interested in going to class, and lunch-counter sit-ins made for unpleasant meals for civil rights opponents and sympathizers alike. These tactics certainly did not rapidly win over public opinion: In 1964, 84% of white Southerners and 64% of non-Southerners thought that civil rights leaders were “trying to push too fast.”

The civil rights movement is only one example (albeit, a very big one). But, across time periods and movements, the evidence is consistent. In a review of 54 peer-reviewed studies published since 2000, Amenta et al. found that “assertive” movements—those that forced their message even on those unwilling to listen—were more likely to have an impact than those that engaged in only symbolic demonstrations.^[3] An earlier review, looking at research reaching back to the 1970s and movements from the 1800s to the present, similarly found that, “overall, the use by social movements of disruptive tactics…seems to increase their potential for change.”^[4]

Disruption works not because it wins bystanders over, but because it imposes real costs on elites and policymakers for ignoring movements’ claims.

Disruption works not because it wins bystanders over, but because it imposes real costs on elites and policymakers for ignoring movements’ claims. Workers won rights to unionization in the 1930s in part because they realized that, thanks to the invention of assembly lines, they could shut down production—and profit-making—with a sit-down strike involving only a handful of participants.^[5] Protesters from the radical gay movement ACT-UP shifted federal funding towards AIDS by injecting their message into spaces and events, like baseball games, where they were far from welcome.^[6]

Given that social movements have only limited resources, a social movement strategy focused on making friends in the general public can be a disastrous one. To take a recent example: Theda Skocpol analyzed the different paths taken by organizations committed to addressing climate change and reforming health care in the early years of the Obama administration.^[7] The former focused on moving the needle of public opinion by running advertising campaigns that emphasized scientific consensus about the importance of addressing climate change. The latter organized state by state to hold vulnerable legislators’ “feet to the fire.” We know how these two approaches fared: Today, climate activists are chaining themselves to the White House gates in a new push for confrontational tactics, while health reformers can bask in one of the largest expansions of government benefits in decades.

None of this is to say that shutting down highways or shouting down politicians, on their own, will ensure BLM’s success. BLM has already claimed some victories, such as getting Bernie Sanders to introduce a platform on “Race and Racial Justice.” But “starting a national conversation” on race—or, in the case of Occupy Wall Street, income inequality—is only the first step to changing public policy and racist behavior. To do that, Black Lives Matter will need organization and a coherent vision for how individual actions and tactics fit into a much broader strategy. Many of the factors that aid movements, like divisions among legislators or a favorable economy providing resources for government action, are out of their control.

In the meantime, though, BLM would be well-served by continuing to threaten consequences—whether electoral or economic—for those in power who remain passive in the face of virulent racism. The odds for structural change are always long, but disruption remains the best bet.