There is widespread agreement that the Australian ballot fundamentally altered the American electoral system. One common approach to test the effects of ballot reform is to examine legislators elected under the party and secret ballot. An alternative research design, which we adopt here, compares changes in the behavior of legislators who were elected under both ballot types. We use this approach to investigate whether ballot reform directly influenced legislators' decisions to seek renomination and their behavior within the institution. Our results raise a number of important implications for understanding the effects of electoral reform on political behavior.