Brazil Chamber of Deputies election 2018 — Results

Overview

The 2018 election to Brazil's Chamber of Deputies, held alongside the first round of the presidential vote on 7 October, produced one of the most fragmented and volatile legislatures in the country's democratic history. The Workers' Party (PT) remained the single largest bloc, but the headline story was the explosive growth of Jair Bolsonaro's previously tiny Social Liberal Party (PSL), which surged from one seat to 52, while traditional establishment parties were punished by voters angry over corruption.

The voting system

The Chamber of Deputies has 513 members elected for four-year terms by open-list proportional representation. Each of the 26 states and the Federal District is a single multi-member constituency, with seats apportioned by population (from a minimum of 8 to a maximum of 70 for São Paulo) and allocated among party lists and coalitions by an electoral quotient. Because voters rank individual candidates within open lists, and because Brazil has dozens of registered parties, the system produces an exceptionally large and splintered chamber in which no party holds anything close to a majority.

The campaign trail

The legislative races were overshadowed by the presidential contest and by the anti-establishment mood that Operation Car Wash had fuelled. Bolsonaro's coat-tails and his social-media reach lifted a slate of political newcomers, military officers and conservative figures onto the PSL ticket. The PT mounted a strong defence in its North-Eastern strongholds, while the centrist PMDB/MDB and PSDB — long the parties of government — haemorrhaged support.

The result

The PT won 56 seats, narrowly the most of any party, but the PSL's leap to 52 on the largest national vote share (11.65%) symbolised the realignment. A long tail of mid-sized parties followed — the Progressives (PP) 37, the PSD and MDB 34 each, the Party of the Republic (PR, later PL) 33, the Socialists (PSB) 32, the PRB (later Republicans) 30, the PSDB and Democrats (DEM) 29 each, the PDT 28. Roughly thirty parties won seats in all, leaving the incoming president to govern through ad-hoc coalitions.

What happened next

The fragmentation forced President Bolsonaro to rely on the "centrão", the bloc of pragmatic centre-right parties that trades legislative support for posts and budget amendments. Tensions with that bloc, and the eventual collapse of the PSL (which Bolsonaro left in 2019 to found a new party), shaped the turbulent politics of his term. The 2018 chamber underlined a structural feature of Brazilian democracy: governing requires the constant assembly of broad, costly multi-party majorities.

Compiled and reviewed from official results by ElectioMap. See our data methodology.