This article offers a first-ever comprehensive empirical assessment of a key Progressive reform, the direct primary, and its impact on competition in American elections. We begin with a review of the problems Progressives diagnosed in the American electoral system and reasons to expect the direct primary to be a pro-competitive, democratizing reform. We then consider prior research into the direct primary and electoral contestation and describe the database of primary and general election outcomes that we have constructed to trace competition in primaries for federal and statewide offices. Finally, we examine the historical trajectory of competition in primary elections, starting with the first decades after the introduction of the reform and then the succeeding decades.
Consistent with the hopes of reformers, we find primary elections indeed provided a forum for contestation for federal and statewide elections. Although primaries were never broadly competitive, even at the outset, they accounted for about a third of the serious electoral tests faced by statewide officeholders and about a fifth faced by U.S. representatives. The role of primaries as a venue for robust contestation, however, was short-lived, as the competitiveness of federal and statewide primaries decreased sharply starting in the 1940s. The last section of this article explores whether two recent developments in American elections—the extension of two-party competition and the rise in the value of incumbency—conspired to temper the contribution of direct primaries to electoral competition.