Brazilian Democratic Movement

The Brazilian Democratic Movement (Portuguese: Movimento Democrático Brasileiro, MDB) is a Brazilian political party. It is considered a "big tent party" and it is one of the parties with the greatest representation throughout the national territory, with the largest number of senators, mayors and city councillors, It has consistently held a large presence in the National Congress since 1988, and also has the largest number of affiliates, with 2,043,709 members as of July 2023.

Originally, the MDB was founded in 1965 as part of an enforced two party system by the Brazilian military dictatorship, being the "consented opposition" — providing an official, but controlled, opposition to the governist National Renewal Alliance (ARENA). With the political opening in the early 1980s the two parties were disbanded and former members of the MDB created the Brazilian Democratic Movement Party (Portuguese: Partido do Movimento Democrático Brasileiro, PMDB), the name by which the party was known until 2018. It was the party of former Presidents of Brazil Tancredo Neves, José Sarney, Itamar Franco and Michel Temer, as well providing support for the governments of Fernando Henrique Cardoso, Luíz Inácio Lula da Silva and Dilma Rousseff, as well as unofficial support for the government of Jair Bolsonaro.

After the redemocratization of Brazil, MDB became a big tent party without a clear ideological program, seeking to have many members from various positions and different interest groups under its wing. It has been considered one of the core members of the Centrão, having supported multiple governing parties since the beginning of the Sixth Brazilian Republic. As such, the party has been criticized and accused of being a cronyistic "physiological party", which focus on negotiating support for the government in exchange for positions, resources and political influence.