A recent study published in the journal Political Behavior suggests that the Black Lives Matter protests of 2020 significantly increased the Democratic vote share in the presidential election that same year. The research provides evidence that peaceful mass mobilization can change public attitudes about racial inequality rather than simply encouraging existing supporters to vote. While the protests initially triggered a conservative backlash, this reaction ultimately shifted into increased progressive support by November.
The authors of the new study sought to better understand exactly how large public demonstrations influence electoral outcomes. Previous research yields conflicting views on whether protests advance or hinder a movement’s goals. Peaceful protests often generate sympathy and shift public opinion toward the demands of the participating group.
At the same time, protests that involve severe disruption can push voters toward conservative politicians who emphasize law and order. The Black Lives Matter demonstrations in the spring of 2020 represented one of the largest mass mobilizations in United States history. Because the movement faced both widespread support and intense criticism, scientists wanted to measure how this massive collective action affected the choices voters made at the ballot box.
“Interestingly, around the 2020 elections we were discussing with my coauthor whether the protests would do anything to the electoral result, so ended up writing a paper about it. More substantively, the 2020 BLM protests represented one of the largest collective action movements in US history, with an estimated 15-26 million participants,” said study author George Melios, a research officer at the London School of Economics.
“Yet there’s an ongoing debate in political science about whether protests ultimately help or hurt their cause—some research shows they generate support for protesters’ goals, while other work suggests violent protests can trigger backlash. We wanted to provide causal evidence on how this historically unprecedented movement affected actual electoral outcomes.”
To measure these political shifts, the researchers analyzed data from 3,053 of the 3,139 counties in the United States. They focused on the two-week window immediately following the death of George Floyd, specifically from May 26 to June 7, 2020. The scientists used protest attendance records from the Crowd Counting Consortium, an organization that tracks public demonstrations across the country.
They paired this information with county voting records from the 2012, 2016, and 2020 presidential elections. Because people in heavily Democratic areas might simply be more likely to protest, the researchers needed a way to separate pre-existing political leanings from the actual effect of the demonstrations. To do this, they used local daily rainfall data from the National Oceanic and Atmospheric Administration.
Rainfall acts as a natural, random event that discourages people from protesting but is otherwise unrelated to a county’s political climate. The researchers looked at how unexpected rainfall during the two-week protest window reduced demonstration size. They then calculated how that weather-driven drop in protest attendance affected local voting patterns in the November election.
To verify their findings, the scientists also used a statistical method that compares the change in voting patterns between counties that experienced protests and those that did not. This method assumes that, without the protests, voting trends in both sets of counties would have continued on similar paths.
They also analyzed survey responses from a Gallup public opinion panel involving 85,106 adults. This public opinion survey ran daily between March and August 2020. Analyzing these daily responses allowed the researchers to track how political identities shifted week by week.
The researchers found that Black Lives Matter protests caused a distinct leftward shift in local voting behavior. In counties that experienced at least one protest, the Democratic vote share increased by an estimated 1.2 to 1.8 percentage points. In a county with 100,000 voters, this shift translates to roughly 1,200 to 1,800 additional votes for the Democratic presidential candidate. In an election decided by narrow margins in key states, the researchers note that shifts of this size are highly meaningful.
The data suggests this shift did not happen because the protests simply increased overall voter turnout. The researchers tested whether protests altered the total number of ballots cast relative to the eligible voting population and found no significant effect. Instead, the protests appear to have genuinely changed the minds of independent or moderate voters.
Surveys showed that protests successfully altered local attitudes regarding historical and modern discrimination. Following the demonstrations, fewer people agreed with the statement that Black Americans should work their way up without special favors. Concurrently, more people agreed that historical slavery created ongoing conditions that make it difficult for Black Americans to succeed in modern society. These shifts in perspective appear to have directly influenced decisions at the ballot box.
“To put this concretely: in a county of 100,000 voters, our estimates suggest protests shifted roughly 1,200-1,800 votes toward Biden,” Melios told PsyPost. “With 40% of US counties experiencing protests, these effects accumulate substantially. Consider that Biden won Georgia by around 12,000 votes and Arizona by about 10,500 — margins well within the range that protest — driven shifts across multiple counties could plausibly explain. So while a 1.5 percentage point shift might sound modest, in an election decided by razor-thin margins in key states, it’s potentially decisive.”
The scientists also noted an unexpected pattern over time regarding public reaction. Survey data from the immediate aftermath of the protests showed a brief decrease in the likelihood that people identified as Democrats. The researchers suggest this initial conservative backlash was likely a reaction to media coverage of property damage or intense disruption.
Over the following weeks and months, however, this initial backlash completely reversed. As immediate disruptions faded from the news cycle, voters appeared to reflect more heavily on the core issues of racial injustice and police brutality. By the time the November election arrived, this reflection resulted in increased support for the Democratic party.
“The temporal dynamics were unexpected,” Melios said. “Immediately after the protests, we observed suggestive evidence of a conservative backlash—increased Republican identification in protest areas. But over the following weeks, this reversed entirely, ultimately producing the progressive shift we observe in the November election. This highlights how evaluations of protest effectiveness can depend critically on when you measure outcomes.”
The researchers also found that the protests tended to have the strongest electoral impact in smaller counties with predominantly white populations and lower average education levels. In massive urban centers, local protests might easily blend into the background of daily city life.
In smaller communities, a local protest is a highly visible event. Seeing neighbors engage in a demonstration can make a strong impression on fellow residents, signaling that racial inequality is a pressing community issue. While these findings are detailed, the researchers note a few potential limitations to their work.
“Mass mobilization can meaningfully shape elections (when peaceful),” Melios explained. “The BLM protests genuinely shifted political preferences—not just by mobilizing existing Democratic voters, but by changing people’s attitudes about racial inequality. Perhaps most importantly, timing matters: we found an initial backlash immediately after the protests that ultimately reversed into increased Democratic support by November.”
As with all research, there are some caveats to consider. The analysis primarily captures how protests affected voting in the specific local counties where they occurred, rather than measuring how national media coverage influenced the country as a whole.
The rainfall-based analysis also specifically identifies effects in places where weather conditions actually influenced protest turnout. This specific focus means the findings might not completely apply to extremely politically active areas where people would protest regardless of the weather.
As for future research, “we’re interested in whether these findings generalize to other protest movements, countries, and historical periods,” Melios told PsyPost. “It also remains an open question whether the BLM movement achieved its primary goal of promoting more equitable treatment in the criminal justice system—that’s an important area for future research.”
“Our results offer encouragement for peaceful collective action. While the immediate aftermath of protests can be turbulent and may even trigger short-term backlash, sustained mobilization can ultimately shift both attitudes and electoral outcomes in meaningful ways.”
The study, “Weather to Protest: The Effect of Black Lives Matter Protests on the 2020 Presidential Election,” was authored by Bouke Klein Teeselink and Georgios Melios.
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