1. For a comprehensive review of the literature published in Brazil until about 1978, see Bolivar Lamounier and Maria D'Alva Gil Kinzo, “Partidos políticos, representação e processo eleitoral no Brasil, 1945–1978,” Boletim Informativo e Bibliográfico de Ciencias Sociais, no. 5 (1978). For a comprehensive review of the post-1978 Brazilian literature, see Olavo Brasil de Lima Júnior, Rogério Augusto Schmitt, and Jairo César Marconi Nicolau, “A produção brasileira recente sobre partidos, eleições e comportamento político: Balanço bibliográfico,” Boletim Informativo e Bibliográfico de Ciências Sociais, no. 34 (second semester 1992):3–66.

2. A partial exception to this rule is Gláucio Dillon Soares's seminal book Sociedade e política no Brasil (São Paulo: Difel, 1973). Soares emphasized the structuring and stability of the party system from 1945 to 1964. Some of the best works that emphasize party weakness in that period are Bolivar Lamounier and Rachel Meneguello, Partidos políticos e consolidação democrática: O caso brasileiro (São Paulo: Brasiliense, 1986); and Phyllis J. Peterson, “Brazilian Political Parties: Formation, Organization, and Leadership,” Ph.D. diss., University of Michigan, 1962.

3. The effective number of parties is a formula that weights the number and size of parties. If three equal parties each have one-third of the seats (or votes), the effective number of parties is 3. If one party has one-half and two parties each have one-quarter, then the effective number of parties is 2.67, reflecting the existence of three parties but the larger share of one. The effective number of parties is equal to 1 divided by the sum of the squares of each party's share of votes or seats. See Markku Laakso and Rein Taagepera, “The Effective Number of Parties: A Measure with Application to West Europe,” Comparative Political Studies 12, no. 1 (Apr. 1979):3–27.

4. My calculations are based on seats rather than on votes.

5. On the post-1961 crisis in the party system, see Wanderley Guilherme dos Santos, Sessenta e quatro: Anatomia da crise (São Paulo: Vértice, 1986); and Maria do Carmo Campello de Souza, Estado e partidos políticos no Brasil (1930 a 1964) (São Paulo: Alfa-Omega, 1976), 139–68.

6. On this point, see Alberto Guerreiro Ramos, A crise do poder no Brasil (Rio de Janeiro: Zahar, 1961); and Lúcia Hippólito, PSD: De raposas y reformistas (Rio de Janeiro: Paz e Terra, 1985).

7. See Soares, Sociedade e política no Brasil; and Souza, Estado e partidos políticos no Brasil (1930 a 1964).

8. Party-system fragmentation refers to the dispersion of seats or votes among parties. It is based on the same information as the effective number of parties but is the mathematical inverse: the sum of the squares of each party's share of votes or seats.

9. Data on electoral volatility support the view that the party system was not well institutionalized. Volatility in presidential elections averaged a high 29.7 percent between 1945 and 1960. Volatility (based on seats) averaged 13.8 percent for elections to the Chamber of Deputies and 25.6 percent for Senate elections. These volatility levels are nonetheless lower than those for the period since 1985.

10. Thomas E. Skidmore, Politics in Brazil, 1930–1964: An Experiment in Democracy (New York: Oxford University Press, 1967).

11. See Lamounier's “Authoritarian Brazil Revisited: The Impact of Elections on the Abertura,” in Democratizing Brazil: Problems of Transition and Consolidation, edited by Alfred Stepan (New York: Oxford University Press, 1989), 43–79.

12. Important aspects of ARENA politicians are analyzed, but without focusing on the party per se, in Frances Hagopian's excellent study, Traditional Politics and Regime Change in Brazil (New York: Cambridge University Press, forthcoming). See also Timothy Power, “The Political Right and Democratization in Brazil,” Ph.D. diss., University of Notre Dame, 1993.

13. On this theme, see also Carlos Alberto Marques Novaes, “PT: Dilemas da burocratização,” Novos Estudos CEBRAP, no. 35 (Mar. 1993):217–37. He emphasizes the PT's growing bureaucratization. See also Leôncio Martins Rodrigues, Partidos e sindicatos: Escritos de sociologia política (São Paulo: Atica, 1990), 7–33. Martins Rodrigues emphasizes the PT's transformation from a party with many workers in leadership positions to one with a highly educated leadership.

14. On the authoritarian nature of parts of the PT Left, see Marilena Chaui, “PT ‘leve e suave‘?” in E agora, PT? Caráter e identidade (São Paulo: Brasiliense, 1986), 43–100.

15. On this point, see Francisco de Oliveira, “Qual é a do PT?” in E agora, PT?, 9–34.

16. Also noteworthy is Rachel Meneguello, PT: A formação de um partido, 1979–1982 (São Paulo: Paz e Terra, 1989).

17. On contemporary Brazil, see Hagopian, Traditional Politics and Regime Change in Brazil, and Power, “The Political Right and Democratization in Brazil.” On conservative parties in Argentina, see Ed Gibson, “Conservative Parties and Democratic Politics: Argentina in Comparative Perspective,” Ph.D. diss., Columbia University, 1992. On centrist parties in Chile, see Timothy R. Scully, Rethinking the Center: Party Politics in Nineteenth- and Twentieth-Century Chile (Stanford, Calif.: Stanford University Press, 1992). On the major centrist party in Brazil between 1945 and 1964, see Hippólito, PSD: De raposas y reformistas; on the major conservative party during the same period, see Maria Victória de Mesquita Benevides, A UDN e o Udenismo: Ambigüidades do liberalismo brasileiro (1945–1965) (Rio de Janeiro: Paz e Terra, 1981).

18. The notion of a hegemonic party system comes from Giovanni Sartori, Parties and Party Systems: A Framework for Analysis (Cambridge: Cambridge University Press, 1976). According to Sartori, in a hegemonic party system, “The hegemonic party neither allows for a formula nor a de facto competition for power. Other parties are permitted to exist, but as second-class, licensed parties…. [T]he hegemonic party will remain in power whether it is liked or not” (p. 230).

19. For further development of this argument, see Scott Mainwaring and Timothy Scully, “Party Systems in Latin America,” in Building Democratic Institutions: Party Systems in Latin America, edited by Mainwaring and Scully (Stanford, Calif.: Stanford University Press, 1995), 1–34, 477–82. My views of the post-1985 Brazilian party system can be found in the same book in “Brazil: Weak Parties, Feckless Democracy,” 354–98, 537–42.