AMHERST, Mass. — Mass shootings can spur higher voter turnout in nearby communities, but the effect is highly localized and doesn't appear to change how people vote for president, according to new findings from researchers at the University of Massachusetts Amherst and the Brennan Center for Justice at NYU Law.
The study, published today in Science Advances , analyzed whether mass shootings motivate Americans to vote—and if they change whom voters support at the polls.
"Mass shootings boost turnout generally, but especially in deeply blue areas [and] without changing minds," says Kelsey Shoub , associate professor of public policy at UMass Amherst. "However, they do seem to move the needle on very specific gun-reform ballot initiatives."
Using data from the Gun Violence Archive and nearly half a billion individual voter records, Shoub and Kevin Morris , senior research fellow at the Brennan Center, built one of the most detailed datasets yet to study this question. They compared turnout in neighborhoods located within 10 miles of mass shootings that occurred shortly before or after the 2016 and 2020 presidential elections.
The results show mass shootings "mobilize local voters," but their effects are limited in scope. Turnout surged by up to 10 percentage points in neighborhoods located within a half mile of a shooting in the weeks before an election. However, that boost disappeared beyond about five miles, indicating that the impact of mass violence on political behavior is highly localized.
The study also found that these turnout increases were concentrated in heavily Democratic areas. Voters in those communities were far more likely to cast ballots after a nearby mass shooting, while turnout in Republican-leaning neighborhoods barely changed.
Despite the increase in participation, the research found no evidence that mass shootings altered presidential vote choices. However, they did identify a potential link between shootings and support for gun-control measures.
In California, precincts located near a mass shooting before the 2016 election were significantly more likely to vote for Proposition 63 , a ballot initiative requiring background checks for ammunition purchases and banning large-capacity magazines. The same pattern did not appear for other liberal ballot measures that year, suggesting that the effect was specific to gun policy.
Previous county-level studies found no connection between mass shootings and voter turnout. By analyzing smaller geographic units—census block groups and precincts—Shoub and Morris found that the political effects of mass shootings are real but geographically constrained.
While mass shootings may not reshape national elections, they can galvanize local communities and strengthen support for specific gun-reform efforts close to where tragedies occur, Shoub notes.
"For people who are looking for some sort of policy change, it might be better to pursue ballot initiatives than to pursue general voting strategies," she adds.
