Why are political brokers responsive to the claims of some voters and not others? Despite an expansive comparative literature on brokers, relatively few studies have systematically scrutinized their downstream responsiveness to clients. Existing literature anticipates brokers will privilege co-partisan and co-ethnic clients, whose reciprocity they can most confidently monitor. In this paper, we argue that brokers must also prioritize clients best positioned to maximize their local reputations for competence. We test our theoretical expectations through a conjoint survey experiment among archetypical urban brokers in the developing world: informal slum leaders. Embedded in local communities, slum leaders spearhead efforts to resist eviction and demand basic services, and encourage electoral support and turnout on behalf of political parties. Our survey of 629 slum leaders across 110 slums in two north Indian cities finds strong evidence of the importance of reputational concerns in driving broker responsiveness. We find more mixed evidence of brokers prioritizing monitoring concerns emphasized by extant literature, highlighted by a marked absence of ethnic favoritism within Indian slums.