Do activities by immigration enforcement agencies suppress or mobilize Hispanic voters? To answer this question, we exploit the sharp discontinuity in the legal authority of United States Customs and Border Protection (CBP) at the boundary of the 100-mile interior US border zone. We find that CBP activities increased Hispanic voter registration and turnout in the 2016 US general election by 1.8pp and 1.5pp, respectively. We suggest that the main mechanism is via personal experiences—observing or hearing about CBP activities—as opposed to elite-driven campaigns that are unlikely to be spatially discontinuous. We also estimate the electoral consequences of CBP activities through a simulation exercise and find a small increase in the Democratic Party's representation in the US Congress.