It sometimes takes decades to find out. --- In the short term, protests can work to the degree that they can scare authorities into changing their behavior. Protests are signals: “We are unhappy, and we won’t put up with things the way they are.” But for that to work, the “We won’t put up with it” part has to be credible. Nowadays, large protests sometimes lack such credibility, especially because digital technologies have made them so much easier to organize. […] Indeed, the past few decades in the United States have featured many large and widespread protests without corresponding immediate change. Large numbers of people marched around the country in early 2003 to oppose the impending invasion of Iraq, but the war and the occupation proceeded anyway in March of that year. The Occupy movement in the United States saw marches in 600 communities and 70 major cities quickly, and then went global, but inequality has gotten worse since then. Neither numbers nor streets are by themselves magic wands for change. […] The current Black Lives Matter protest wave is definitely high risk through the double whammy of the pandemic and the police response. The police, the entity being protested, have unleashed so much brutality that in just three weeks, at least eight people have already lost eyesight to rubber bullets. One Twitter thread dedicated to documenting violent police misconduct is at 600 entries and counting. […] In the long term, protests work because they can undermine the most important pillar of power: legitimacy. Commentators often note that a state can be defined by its monopoly on violence, a concept going back to the philosopher Thomas Hobbes and codified by the sociologist Max Weber. But the full Weber quote is less well known. Weber defined the state by its “monopoly of the legitimate use of physical force.” The word legitimate is as important as the words physical force, if not more. Especially in the modern world, that monopoly on violence isn’t something that self-perpetuates. Violence doesn’t just happen; it has to be enacted and enabled by people. The Soviet Union did not fall because it ran out of tanks to send to Eastern Europe when the people there rebelled in the late 1980s. It fell, in large part, because it ran out of legitimacy, and because Soviet rulers had lost the will and the desire to live in their own system. Compared with Western democracies, their system wasn’t delivering freedom or wealth, even to the winners. If the loss of legitimacy is widespread and deep enough, the generals and police who are supposed to be enacting the violence can and do turn against the rulers (or, at least, they stop defending the unpopular ruler). Force and repression can keep things under control for a while, but it also makes such rule more brittle. Legitimacy, not repression, is the bedrock of resilient power. A society without legitimate governance will not function well; people can be coerced to comply, but it’s harder to coerce enthusiasm, competence, and creativity out of a discouraged, beaten-down people. Losing legitimacy is the most important threat to authorities, especially in democracies, because authorities can do only so much for so long to hold on to power under such conditions. Maybe they can stay in power longer in part through obstacles such as voter repression, gerrymandering, and increasing the power of unelected institutions, but the society they oversee will inevitably decline, and so will their grasp on power. In that light, focusing on legitimacy as the most robust source of power, it becomes clear that the Black Lives Matter movement has been quite successful in its short life. It should first be noted: This is a young movement, but it did not start this year. The current wave of high-risk protests is a crest in a movement that goes back to the 2012 killing of Trayvon Martin in Florida, and that spread nationwide after the protests in Ferguson, Missouri, over the 2014 killing of Michael Brown. Understood in their proper historical context, Black Lives Matter protests are the second civil-rights movement in postwar America, and measured in that light, they are more and more successful in the most important metric: They are convincing people of the righteousness of their cause. In the long run, that’s of profound importance. […] Protests also work because they change the protesters themselves, turning some from casual participants into lifelong activists, which in turn changes society. This is especially salient when a movement opposing police brutality and misconduct is met with more police brutality and misconduct. Peaceful protesters across the country have endured tear gas, rubber bullets, and batons, and this is no doubt part of the reason people are changing their minds. If the police will do this to protesters in broad daylight with cameras in so many hands, what else is happening to black or other vulnerable communities when nobody is around to film the interaction? This gets to the final reason that protests work: Collective action is a life-changing experience. To be in a sea of people demanding positive social change is empowering and exhilarating. Protests work because they sustain movements over the long term as participants bond during collective action. […] Do protests work? Yes, but not simply because some people march in the streets. Protests work because they direct attention toward an injustice and can change people’s minds, a slow but profoundly powerful process. Protests work because protesters can demonstrate the importance of a belief to society at large and let authorities understand that their actions will be opposed, especially if those protesters are willing to take serious risks for their cause. Protests work because they are often the gateway drug between casual participation and lifelong activism. And, sometimes, protests work because, for that moment, the question in the minds of the protesters is not whether they work short term or long term, but whether one can sit by idly for one more day while a grave injustice unfolds. And perhaps that’s the most powerful means by which protest works: when the cause is so powerful that the protesters don’t calculate whether it works or not, but feel morally compelled to show up and be counted.

In that context, the fact that this shield wall, unlike historical shield walls, *cannot advance* makes its defensive nature instantly understandable to most observers. It reinforces the contrast between the aggressive, violence-initiating police and the defensive violence-receiving protesters, while at the same time allowing the protest to engage in what is essentially 'force protection' - keeping its people on the streets, out of jail, and out of a hospital, where they can continue to pursue the protest's agenda.