A deep dive into Brazil’s fragmented party system

Brazilian Congress building. Photo: R.M. Nunes/Shutterstock

Brazil has a huge number of political parties, which make up a highly fragmented political system. Getting a handle on who is who can be a tricky task. Here we present certain patterns and tendencies, categorizing the parties according to the demographics of party memberships, party financing, recent performance, and histories.

All parties were not created equal — the oldest and biggest parties have the most nationwide reach and play an outside role in political proceedings today.

Party membership

Party membership is the simplest measure by which to gauge the size of a party. It indicates how many voters are strongly attached to a party, and — in a context in which politicians frequently jump ship — it tells us which groupings candidates see as good vehicles for their aspirations.

Surprisingly, parties hardly lose any members over the years — with very few exceptions. Growth, on the other hand, takes place in biannual cycles, corresponding to municipal and general elections. Growth is usually greater during municipal election cycles — when there are more offices up for grabs, and thus more candidates running. That behavior is epitomized by the Brazilian Socialist Party (PSB), the Green Party (PV), and Podemos.

Many parties are not mass organizations made up of supporters and militants, but rather are primarily electoral vehicles, whose membership is therefore made up of existing or aspiring politicians.

Only a small number of parties grow at a fast pace — even outside of electoral cycles. These tend to be smaller and more explicitly ideological organizations, such as the Socialism and Freedom Party (Psol) or libertarian group Novo.

In the rare cases that a party loses members, it is usually due to an internal split that leads to a stampede to another party. The founding of the Social Democratic Party (PSD) in 2011, for example, drained members from Democratas (DEM).

Another particular case is that of the Workers’ Party. Between 2014 and 2019, the party saw its membership stagnate. While political crises and corruption scandals led to massive disaffiliation, natural growth cycles compensated for these losses.