Basic Downsian theory predicts candidate convergence toward the views of the median voter in two-candidate elections. Common journalistic wisdom, moreover, leads us to expect these centripetal pressures to be strongest when elections are expected to be close. Yet, the available evidence from the US Congress disconfirms this prediction. To explain this counterintuitive result, we develop a spatial model that allows us to understand the complex interactions of political competition, partisan loyalties, and incentives for voter turnout that can lead office-seeking candidates, especially candidates in close elections, to emphasize policy appeals to their voter base rather than courting the median voter.