Minimum Winning Electoral Coalitions Under Presidentialism: Reality or Fiction? The Case of Brazil

This article studies the motivations of party leaders to form "minimum winning" electoral coalitions—alliances that cease to be winning if one member is subtracted. In Brazil, concurrent elections stimulate political actors' coordination, and electoral alliances are allowed. In 2002 and 2006, moreover, the Electoral Supreme Court obliged those parties with presidential candidates to replicate this electoral arrangement in the district. Under "verticalization," parties with presidential candidates could not form alliances with rival parties in the concurrent legislative and gubernatorial elections. Verticalization arguably pushed party leaders to form minimum winning electoral coalitions. This new rule forced them to reconsider the contributions of each possible ally in the elections for president, federal deputy, and governor. Examining the elections from 1998 to 2006, this study finds that under verticalization, while parties did form more electoral coalitions with those partners they considered crucial to win, they did so at the expense of policy.