This article examines the disruptive effect of coups on party systems. Coups are junctures that can increase polarization and explain party system disruption—measured in the dynamics and determinants of inter-party competition. Until recently, scholars labeled Honduras’s party system as one of Latin America’s most institutionalized, albeit based on clientelist linkages. The 2009 coup against President Manuel Zelaya abruptly ended decades of two-party rule. We use presidential and legislative election results and the AmericasBarometer surveys to assess the coup’s impact on vote choice. The evidence shows that the coup jumpstarted an ideological alignment in a party system where clientelism had historically thrived.