Are ordinary citizens or political party leaders better positioned to select candidates? While the direct vote primary system in the United States lets citizens choose, it is exceptional, as the vast majority of democracies rely instead on party officials to appoint or nominate candidates. Theoretically, the consequences of these distinct design choices on the selectivity of the overall electoral system are unclear: while party leaders may be better informed about candidate qualifications, they may value traits—like party loyalty or willingness to pay for the nomination—at odds with identifying the best performer. To make progress on this question, we partnered with both major political parties in Sierra Leone to experimentally vary how much say voters, as opposed to party officials, have in selecting Parliamentary candidates. We find evidence that more democratic selection procedures increase the likelihood that parties select the candidate most preferred by voters, favor candidates with stronger records of local public goods provision, and alter the allocation of payments from potential candidates to party officials.