Party switching has received considerable attention in academic literature in recent years, especially in Brazil. Surprisingly, however, very little is known about the reasons why senators decide to change their party affiliation. Against this backdrop, this study takes the first step and sheds light on the matter by investigating what is behind senatorial party defection in Brazil. Overall, the results indicate that ideological distance between senators and parties emerges as the primary factor explaining the switch, although this relationship is slightly conditioned by office and vote considerations. However, the findings also highlight how the behaviour of senators changes according to the degree of the seats up to contest in the upcoming elections (i.e. one-third or two-thirds of the chamber). Thus, our results add another piece to understanding the party switching puzzle in Brazil and bring important implications for legislative studies and legislative behaviour.
AlbalaA (2017) Bicameralism and Coalition Cabinets in Presidential Polities: A Configurational Analysis of the Coalition Formation and Duration Processes. The British Journal of Politics and International Relations19 (4): 735–754.
2.
AldrichJHBiancoWT (1992) A Game-Theoretic Model of Party Affiliation of Candidates and Office Holders. Mathematical and Computer Modelling16 (8–9): 103–116.
3.
AmesB (2002) The Deadlock of Democracy in Brazil. Ann Arbor, MI: University of Michigan Press.
4.
Amorim NetoO (2019) Cabinets and Coalitional Presidentialism. In: AmesB (ed.) Routledge Handbook of Brazilian Politics. New York: Routledge, pp.293–312.
5.
AraújoPM (2012) O bicameralismo no Brasil: argumentos sobre a importância do senado na análise do processo decisório federal. Política & Sociedade11 (21): 83–135.
6.
AraújoPM (2014) Bicameralismo e poder Executivo no Brasil: revisão de projetos presidenciais entre 1989-2010. Opinião Pública20 (1): 67–95.
7.
ArriolaLRChoiDDDavisJM, et al. (2022) Paying to Party: Candidate Resources and Party Switching in New Democracies. Party Politics28 (3): 507–520.
8.
AvritzerL (2019) The Double Crisis of Representation and Participation in Brazil. Representation55 (3): 251–263.
9.
BatistaM (2018) Who Gets What and How Does It Matter? Importance-Weighted Portfolio Allocation and Coalition Support in Brazil. Journal of Politics in Latin America10 (3): 99–134.
10.
BatistaM (2023) Power-Sharing, Presidential Style: Issue Salience and Portfolio Allocation in Multiparty Presidential Systems. Political Research Quarterly76 (2): 915–930.
11.
BatistaMPowerTJZuccoC (2024) Be Careful What You Wish For: Portfolio Allocation, Presidential Popularity, and Electoral Payoffs to Parties in Multiparty Presidentialism. Party Politics30 (4): 622–636.
12.
BerryWDGolderMMiltonD (2012) Improving Tests of Theories Positing Interaction. The Journal of Politics74 (3): 653–671.
13.
BorgesA (2015) Nacionalização Partidária e Estratégias Eleitorais no Presidencialismo de Coalizão. Dados58 (3): 651–688.
14.
BorgesATurgeonM (2019) Presidential Coattails in Coalitional Presidentialism. Party Politics25 (2): 192–202.
CamerloMMartínez-GallardoC (2022) ¿Por qué son importantes los ministerios importantes? Un marco de análisis. Política y Gobierno29 (1): 1–19.
17.
ChacónMRobinsonJATorvikR (2011) When Is Democracy an Equilibrium? Theory and Evidence from Colombia’s La Violencia. Journal of Conflict Resolution55 (3): 366–396.
18.
CoutoLAlbalaA (2023) A Coalescência Revisitada: O Cálculo Presidencial no Bicameralismo. Dados66 (4): 1–45.
19.
DaminCJr (2015) Migração partidária na Câmara dos Deputados em 2013. Debate: Periódico de Opinião Pública e Conjuntura Política7 (1): 33–49.
20.
DesposatoS (2006) Parties for Rent? Ambition, Ideology, and Party Switching in Brazil’s Chamber of Deputies. American Journal of Political Science50 (1): 62–80.
21.
DesposatoSScheinerE (2008) Governmental Centralization and Party Affiliation: Legislator Strategies in Brazil and Japan. American Political Science Review102 (4): 509–524.
22.
DinizS (2000) As migrações partidárias e o calendário eleitoral. Revista de Sociologia e Política: 31–48.
23.
DuvergerM (1981) Les Partis Politiques. Paris: PUF.
24.
EpsteinDJ (2009) Clientelism Versus Ideology: Problems of Party Development in Brazil. Party Politics15 (3): 335–355.
25.
FashagbaJ (2014) Party Switching in the Senate Under Nigeria’s Fourth Republic. The Journal of Legislative Studies20 (4): 516–541.
26.
FerreiraMC (2011) As migrações partidárias e a correlação de forças na câmara dos deputados (1995-2006). Revista de Sociologia e Política19 (38): 205–215.
27.
Flório LimaBBodetMA (2023) The Effects of Personal Campaign Financing on Party Defection: Evidence from Brazil. Electoral Studies84: 102649.
28.
FreitasA (2008) Infidelidade partidária e representação política: alguns argumentos sobre a migração partidária no Brasil. Caderno CRH21 (52): 37–45.
29.
FreitasA (2012) Migração partidária na Câmara dos Deputados de 1987 a 2009. Dados55 (4): 951–986.
30.
GeorgeABennettA (2005) Case Studies and Theory Development in the Social Sciences. Cambridge: MIT Press.
31.
HellerWBMershonC (2005) Party Switching in the Italian Chamber of Deputies, 1996–2001. The Journal of Politics67 (2): 536–559.
32.
HiroiT (2008) The Dynamics of Lawmaking in a Bicameral Legislature: The Case of Brazil. Comparative Political Studies41 (12): 1583–1606.
33.
HottHACFSakuraiSN (2021) Party Switching and Political Outcomes: Evidence from Brazilian Municipalities. Public Choice187 (3–4): 403–438.
34.
IzumiMY (2016) Governo e Oposição no Senado Brasileiro (1989-2010). Dados59 (1): 91–138.
35.
KerevelYP (2014) Loyalty and Disloyalty in the Mexican Party System. Latin American Politics and Society56 (03): 93–117.
36.
KleinE (2021) Explaining Legislative Party Switching in Advanced and New Democracies. Party Politics27 (2): 329–340.
37.
Latinobarómetro (2023) Informe Latinobarómetro 2023: La recesión democrática de América Latina. Santiago: Corporación Latinobarómetro.
38.
LlanosMNolteD (2003) Bicameralism in the Americas: Around the Extremes of Symmetry and Incongruence. The Journal of Legislative Studies9 (3): 54–86.
39.
LucasKSamuelsD (2010) The Ideological Coherence of the Brazilian Party System, 1990-2009. Journal of Politics in Latin America2 (3): 39–69.
40.
MainwaringSPowerTJBizzarroF (2018) The Uneven Institutionalization of a Party System: Brazil. In: MainwaringS (ed.) Party Systems in Latin America: Institutionalization, Decay, and Collapse. Cambridge University Press, pp.164–200.
41.
MeloCR (2004) Retirando as cadeiras do lugar: migração partidária na Câmara dos Deputados, 1985-2002. Belo Horizonte, Brazil: Editora UFMG, Universidade Federal de Minas Gerais.
42.
MershonCShvetsovaO (2008) Parliamentary Cycles and Party Switching in Legislatures. Comparative Political Studies41 (1): 99–127.
43.
MüllerWCStrømK (eds) (1999) Policy, Office, or Votes?: How Political Parties in Western Europe Make Hard Decisions. Cambridge University Press.
44.
NeivaPRP (2006) Os determinantes da existência e dos poderes das câmaras altas: federalismo ou presidencialismo. Dados49 (2): 221–253.
45.
NeivaPRPSoaresMM (2013) Senado brasileiro: casa federativa ou partidária?Revista Brasileira De Ciências Sociais28 (81): 97–115.
NovaesLM (2018) Disloyal Brokers and Weak Parties. American Journal of Political Science62 (1): 84–98.
48.
O’BrienDZShomerY (2013) A Cross-National Analysis of Party Switching: Party Switching. Legislative Studies Quarterly38 (1): 111–141.
49.
PintoL (2015) The Time Path of Legislative Party Switching and the Dynamics of Political Competition: The Italian Case (1996-2011). The Journal of Legislative Studies21 (3): 323–341.
50.
PooleKTRosenthalH (2001) D-Nominate after 10 Years: A Comparative Update to Congress: A Political-Economic History of Roll-Call Voting. Legislative Studies Quarterly26 (1): 5–29.
51.
RadeanM (2019) Sometimes You Cannot Have It All: Party Switching and Affiliation Motivations as Substitutes. Party Politics25 (2): 140–152.
52.
RadeanM (2022) Perfect Timing: Leveraging the Timing of Defection to Assess the Effect of Electoral Rules on Party Switching. Party Politics28 (4): 666–679.
53.
ReedSRScheinerE (2003) Electoral Incentives and Policy Preferences: Mixed Motives Behind Party Defections in Japan. British Journal of Political Science33 (3): 469–490.
54.
RozoSVQuintanaAUrbinaMJ (2023) The Electoral Consequences of Easing the Integration of Forced Migrants. World Bank Group: Policy Research Working Paper.
55.
SamuelsDZuccoC (2018) Partisans, Antipartisans, and Nonpartisans Voting Behavior in Brazil. Cambridge, MA: Cambridge University.
56.
TelesCS (2015) Mudanças entre partidos na câmara dos deputados: sazonalidade e o impacto da fidelidade partidária. E-Legis16: 56–78.
57.
VolpiE (2019) Ideology and Party Switching: A Comparison of 12 West European Countries. Parliamentary Affairs72 (1): 1–20.
58.
ZuccoCPowerTJ (2024) The Ideology of Brazilian Parties and Presidents: A Research Note on Coalitional Presidentialism Under Stress. Latin American Politics and Society66 (1): 178–188.
59.
ZuccoCBatistaMPowerTJ (2019) Measuring Portfolio Salience Using the Bradley–Terry Model: An Illustration with Data from Brazil. Research & Politics6 (1): 205316801983208.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
