Learning about challengers

We examine a political agency problem in repeated elections where an incumbent runs against a challenger from the opposing party, whose policy preferences are unknown by voters. We first ask: do voters benefit from attracting a pool of challengers with more moderate ideologies? When voters and politicians are patient, moderating the ideology distribution of centrist and moderate politicians (those close to the median voter) reduces voter welfare by reducing an extreme incumbent's incentives to compromise. We then ask: do voters benefit from informative signals about a challenger's true ideology? We prove that giving voters informative, but sufficiently noisy, signals always harm voters, because they make it harder for incumbents to secure re-election.