35 pages


Abstract: This paper develops a formal theory that combines power-maximizing "Leviathan" political parties with well-defined imperfections in the political process. The model implies that both parties tend to make government larger as their likelihood of electoral victory increases. Empirical tests on state-level data confirm this prediction. Racing the Leviathan hypothesis against alternatives theories of party motivation indicates that both the Leviathan and the "contrasting ideologies" views have some degree of validity.