In many Western democracies, political parties have moved away from the traditional model of leadership selection via party conventions. There has been much debate on whether the widening of selectorates in party primaries has strengthened or weakened intra-party democracy. But the introduction of primaries is also puzzling. Why do party elites sometimes relinquish their exclusive ability to select leaders and allow party members, or even sympathizers, to participate in this process?
The paper looks at two multilevel countries, Germany and Spain, as representatives of “second” and “third wave” democracies to explain when and where primary elections take place. Despite their differences, in both countries the mainstream parties have sometimes organized primaries, primarily at the regional level, for their leaders’ selection. Thanks to a database on party primaries built by the authors, the paper analyzes the background of this process and reviews the most common explanations offered by the current literature. Its preliminary results show that primaries do not take place when parties want to regain power, or party chairs to secure their nomination, as is commonly believed, but when party elites are internally divided.