Survey data suggest that a high proportion of Chinese congress delegates sit concurrently in two or more congresses. While dual mandates are not unusual in democracies, the literature has failed to notice their existence in China, let alone theorize or analyze them. We turn to the political science literature on assemblies under authoritarianism to guide our analysis of survey data for 3,008 county congress delegates, half of whom are concurrent ones. We show that dual mandates amplify some voices and not others in ways consistent with two perspectives in the literature. Dual mandates amplify information from citizens at the grassroots upward toward governments: More delegates with deep community roots representing poor, rural, remote districts sit concurrently in county and lower-level congresses. Dual mandates also coopt influential groups posing a potential challenge to ruling party power: They amplify the influence of private entrepreneurs, more of whom sit concurrently in county and prestigious higher-level congresses.