Chapter 3 distills the logic and mechanisms by which citizens help to sustain relational clientelism.Although these ongoing exchange relationships are relatively resilient to many challenges facing electoral clientelism, their survival is imperiled by the possibility that citizens or politicians may engage in opportunistic defection.Citizens may renege on their vote promises, and politicians may renege on their promises of material benefits.Voters often undertake purposive actions to mitigate this dual credibility problem, and thereby fortify relational clientelism. Vulnerability frequently motivates clients to do so, as clientelist relationships provide an important form of informal insurance when the state fails to provide an adequate social safety net.This theoretical chapter examines two citizen mechanisms—declared support and requesting benefits. Building on a signaling model, it examines how citizens declare support to transmit meaningful information about the credibility of their vote promises. In addition, it elaborates the logic by which citizens can screen against politicians who are unlikely to follow through on promises of benefits beyond election campaigns.