The Chamber elects its members by proportional representation, with seats distributed among Brazil's 26 states and the Federal District according to population. No delegation, however, may hold fewer than eight seats or more than seventy. Sao Paulo, the most populous state, maxes out at seventy. Roraima, tucked into the Amazon basin against Venezuela, gets the minimum eight despite having only about 650,000 residents. The asymmetry is intentional. Framers of the 1988 constitution worried about Sao Paulo and Rio dominating the legislature, so they capped the large states and floored the small ones. The result is that a Roraima deputy represents roughly 51,000 citizens while most deputies nationally represent about 362,000 - a seven-to-one ratio that favors the Amazonian and Northeastern states against the industrialized Southeast. Every ten years, the Brazilian Institute of Geography and Statistics conducts a census, and the seats are reapportioned.

Elections for the Chamber of Deputies are held every four years, and all 513 seats are up at once. There are no staggered terms like the U.S. Senate - Brazil's lower house turns over, or confirms itself, in a single national vote. The ballot is famously difficult for voters. Because of the proportional representation system, citizens vote for an individual candidate, and those votes flow to party or coalition totals that determine how many seats each list wins. A voter may choose a popular deputy, only to see that deputy's surplus votes elect an unknown colleague further down the list. It is a system that rewards charismatic vote-getters - pastors, celebrities, former police officers, athletes - and fills the Chamber with a mosaic of personalities. Twenty-plus parties typically hold seats, and no party has come close to an outright majority in the democratic era.

Because no party commands a majority, governance runs through blocs and leaders. Four key positions structure the politics of the chamber floor. The Government Leader speaks for the cabinet in session. The Majority Leader is chosen by the bloc of parties that generally supports the cabinet, often broader than the Government Leader's constituency. The Opposition Leader heads the largest party that opposes the current government. The Minority Leader represents the broader opposition bloc. These four speak first in debates, negotiate the agenda, and allocate speaking time to their members. The actual legislative work happens in committees - permanent, temporary, or special inquiry commissions - where bills are drafted, witnesses called, and deals brokered. The chairs of these committees are divided among the parties in proportion to their bench size, which means every reapportionment after an election triggers a round of committee reallocation.

Running the chamber is the Mesa Diretora - the Bureau or Board - a small team elected by the deputies every two years. The Bureau holds procedural power: it sets the calendar, rules on points of order, and oversees the institution's budget and staff. The current Bureau, elected on February 1, 2025, seated Hugo Motta of the Republicanos party from Paraiba as President - the chamber's chief officer, whose rulings can shape which bills reach the floor. Altineu Cortes of Rio de Janeiro serves as First Vice-President, Elmar Nascimento of Bahia as Second Vice-President, and the secretariat runs through Carlos Veras of Pernambuco (First Secretary), Lula da Fonte of Pernambuco (Second), Delegada Katarina of Sergipe (Third), and Sergio Souza of Parana (Fourth). The geography of the Bureau - members drawn from all regions - is deliberate, though political bargaining produces it more than any rule requires.

From the floor of the Chamber, the view is pure Niemeyer. Concrete curves overhead, carpet the color of Brazilian savanna earth, a round seating plan that echoes the dome above. There is no center aisle, no fixed partisan architecture - deputies sit together in party blocs by convention, not because the room dictates it. Television cameras from the parliamentary channel TV Camara broadcast debates live. Electronic voting panels record every member's choice in seconds, a system that in principle eliminates the old filibuster tactics. In practice, the rhythm of the chamber is set by presidential speeches, leader interventions, and the endless procedural motions that Brazilian parliamentary law permits. Outside the building, on the plaza that Costa designed to frame the Three Powers - Congress, Planalto Palace, Supreme Court - the capital's other two branches can watch the upward bowl fill and empty on four-year cycles, the shape of a democracy still finding its rhythm less than a century into its republican life.