The logic of party switching

The impact of the far right on the Brazilian Legislature

Abstract

This article examines the dynamics of party switching underlying the rise of the far right in the Brazilian legislature, focusing on federal deputies who joined Jair Bolsonaro's parties across two electoral cycles – the PSL (Partido Social Liberal, Social Liberal Party) in 2018 and the PL (Partido Liberal, Liberal Party) in 2022. Drawing on an original dataset linking over 22,000 candidacies between 2014 and 2022 through individual taxpayer identification numbers (CPF), we construct a novelty index for party lists and map migration flows using Sankey diagrams. We then propose a typology distinguishing five profiles: loyalists, migrants, newcomers/outsiders, traditional PL members, and opportunists. Logistic regression and OLS (ordinary least squares) models show that loyalty to Bolsonarism was electorally rewarding: loyalists – who followed Bolsonaro in his move to the PL – and opportunists – who joined the PL from other parties – obtained substantially better electoral outcomes than migrants who defected to other parties. The PSL in 2018 exhibited an exceptionally high novelty index (0.91), with 75% of its elected deputies lacking prior electoral experience, whereas the PL in 2022 showed greater institutionalization (novelty index of 0.71) and a substantial influx from the PSL (31.7% of all migrants). Contrary to the literature that attributes party switching in weakly institutionalized systems exclusively to opportunistic motivations, Bolsonarism established political and identitarian ties strong enough to retain significant parliamentary support despite organizational rupture, producing structural effects on legislative representation and reshaping strategic calculations beyond formal party organizations.

Keywords: Party Switching; Far Right; Bolsonarism; Brazilian Party System; Linear Regression.