Résumé : We study how demonstrating against a far-right candidate changes the behavior of voters and ultimately impacts election results. To do so, we focus on the 2002 French runoff presidential elections which pitted far-right candidate Jean-Marie Le Pen against the incumbent, Jacques Chirac. Between the two rounds of the election, demonstrators protested Le Pen’s quest for power at roughly 300 demonstrations. Using rainfall as an exogenous source of variation in demonstration attendance across municipalities, we find that larger protests reduced the number of votes for Le Pen and the number of abstentions and blank or invalid ballots, and increased the number of votes for Chirac. We show that this positive effect on voting for Chirac results from left-wing voters who did not cast a blank or invalid ballot and right-wing voters who switched from Le Pen to Chirac. Next, we focus on the mechanisms behind these results to find that the 2002 demonstrations both reduced support for the policies advocated by Le Pen and signaled that voting for him was socially undesirable. Finally, we provide evidence that demonstrations affected voting mainly through local media coverage and spread out beyond the municipalities that hosted the demonstrations.