The 1946 election for Venezuela's National Constituent Assembly marked the beginning of democratic electoral processes and the modern party system in that country. Although interrupted by ten years of dictatorship (1948-1958), nine national elections for president and parliament have been held since 1946.1 In conjunction with these elections, the Venezuelan party system has passed through four stages: a predominant party system (1945-1948), a limited multiparty system (1958-1973), an attenuated two-party system (1973-1993), and recently, the return to a limited multiparty system (1993-) (Sartori 1976). The objective of this essay is to determine what factors explain the evolution of the Venezuelan party system. Without neglecting the specific characteristics of each stage, the study centers on the structural attributes of the Venezuelan political system that can present a global picture of the process. The destruction of traditional political loyalties during the regime of Juan Vicente G6mez (1908-1935) left a political vacuum (Levine 1973, 19) that new political forces ultimately filled. During the period 1936-1947, the vacuum was filled by organizations led by leaders from the student movement. But in the trienio elections (1945-1948), a new system of party loyalties arose that had strong, lasting effects.2 The original framework of moder party loyalties in Venezuela was first expressed in the elections for the Constituent Assembly in 1946. A predominant party system appeared at this time.3 During the dictatorship (1948-1958) and the transitionary period to democracy in 1958, the 1947 framework persisted but was modified by sociodemographic changes that uprooted rural allegiances and made volatile a sizable sector of the electorate (Urbaneja 1992, 202; Baiez 1981, 208).4 After 1958, the original party landscape incorporated new political forces, giving rise to a multiparty system. During this stage, an institutional framework based on