Competitive elections are essential to representative democracy. Competition in U.S. House elections is low in part because incumbents have strategic advantages that deter strong potential candidates from running. Many observers conclude that incumbents retain their seats without full accountability to the electorate, but the mechanisms of deterrence have never been fully explored from the perspective of strong potential candidates. Based on a survey of potential House candidates designed to capture perceptions of incumbents' personal quality and reelection prospects, we find strong evidence for the “strategic politicians” thesis (Black 1972; Jacobson and Kernell 1983). We extend the logic of the strategic model first by showing that incumbents' reelection prospects are affected by their personal quality and second by demonstrating that incumbents' personal qualities deter strong challengers from running, independent of their electoral prospects. Our findings prompt us to suggest revisions to our understanding of competition and representation in contemporary House elections.