<p>Incumbent politicians are often assumed to prioritize appeasing voters for re-election, but their policy positions may not be solely based on this. We examine the impact of the value associated with winning on incumbent strategy, party discipline, and polarization. This value depends on both the chosen policy position and the quality of congressional committee assignments, which are themselves influenced by policy. To understand these forces, we build and estimate a novel model that captures the importance of policy, congressional committees, and endogenous valuations. Through counterfactual analysis, we explore how party leadership can leverage committee assignments to influence members of Congress. We find that more valuable committee placements increase the value of winning, while ideological effects are more subtle. Overall, these forces provide only slight incentives for policy moderation.</p>