Do representatives and senators respond to the critiques raised by their challengers? This study, one of the first to explore how legislators' experiences as candidates shape their subsequent behavior as policy makers, demonstrates that they do. Winning legislators regularly take up their challengers' priority issues from the last campaign and act on them in office, a phenomenon called 'issue uptake'. This attentiveness to their challengers' issues reflects a widespread and systematic yet largely unrecognized mode of responsiveness in the US Congress, but it is one with important benefits for the legislators who undertake it and for the health and legitimacy of the representative process. This book provides fresh insight into questions regarding the electoral connection in legislative behavior, the role of campaigns and elections, and the nature and quality of congressional representation.