We assess whether quality challengers in state supreme court elections have a significant impact on the electoral successes of incumbents and whether the electorate seemingly makes candidate-based evaluations in these races. To address these questions, we examine 208 elections to the states' highest courts from 1990 through 2000 in the 21 states using partisan or nonpartisan elections to staff their benches. From a Heckman two-stage estimation procedure that takes into account factors influencing challengers' decisions to run as well as factors affecting the electorate's choices among candidates, we find that quality does matter. Experienced challengers significantly lessen the electoral security of incumbents, and the electorate appears to evaluate challengers' qualifications. These findings stand in stark relief to traditional notions that the electorate is incapable of responding to candidate stimuli beyond incumbency and that judicial elections inherently are an ineffective means for securing popular control over the bench.