To caucus or primary? Why state parties change their presidential nomination contests

Abstract Presidential nominations are generally perceived to be under the control of primary voters and caucus‐goers, with party organizations themselves largely powerless to steer outcomes. However, parties are highly active in the background, often switching contests between primaries and caucuses or vice versa in order to influence the nomination. Despite the popular narrative of parties becoming more internally democratic and abandoning caucuses, we find numerous instances of states moving from primaries to caucuses. We examine state party switches between caucuses and primaries between 1980 and 2024, testing various theories of party change. This approach yields few systematic conclusions. Therefore, we shift to examining contemporaneous coverage of state party switches using an inductive qualitative approach, revealing a complex and dynamic nomination system and a variety of reasons why state parties choose one form of contest over another. These findings catch state parties in the act of trying to control nomination contests in surprisingly overt ways.