After the 2021 State Duma elections, the Communist Party of Russia Federation (KPRF) re-appeared on the Russian political landscape as a new political force with new faces and creative local campaigns. How and why were the communists being treated by most of the analysts and voters as systemic and rather passive opposition successfully accumulated political resistance and grievances at the polls in September 2021? In this study, we argue that mobilization against the pension reform in 2018 proved to be the crucial determinant of the electoral outcomes three years later. The latter provides evidence that protests bring about long-term consequences on voting behavior not only in democracies, but also in autocratic states. We rely on the original dataset on protests in 381 large Russian cities (more than 20,000 residents) that took place in Summer-Fall 2018 merged with the electoral data of the Duma elections in 2016 and 2021.