Do representatives and senators respond to the critiques raised by their challengers? This study, exploring how legislators' experiences as candidates shape their subsequent behavior as policymakers, demonstrates that winning legislators regularly take up their challengers' priority issues from the last campaign and act on them. This attentiveness to their challengers' issues reflects a widespread and systematic yet largely unrecognized mode of responsiveness in the U.S. Congress. Tracy Sulkin reveals the important benefits for these legislators as well as the health and legitimacy of the representative process.