Does the populist radical right benefit from increased electoral mobilization? Integrating theories of political grievances with accounts of party competition in Western Europe, we contend that the populist right gains advantage from increased electoral mobilization, but that this effect is conditional on political disaffection. We draw on a novel panel dataset (2009-2019) of more than 10,000 German municipalities and city districts to study the implications of turnout surges as a function of pre-existing levels of political disaffection in a difference-in-differences design. The results demonstrate that turnout surges benefit the populist right "Alternative fur Deutschland" (AfD) in contexts of widespread political distrust. In contrast, increased mobilization acts to depress its electoral fortunes in communities marked by low baseline levels of political disaffection. In shedding light on the interplay between political disaffection and electoral mobilization, this study has important implications for understanding the surge of the populist right in established democracies.