Brazil has lived within the shadow of military rule almost ever since this futuristic capital was founded 24 years ago. But last weekend, Brasilia had the fragrance of democracy in early bloom.
Delegates from two political parties and 23 Brazilian states cast paper ballots as youths in T-shirts banged out samba rhythms and shouted political slogans.
Public squares were strewn with campaign propaganda, despite an official ban on distributing campaign literature.
For the first time in 20 years, two civilians were chosen by their parties to vie to replace the country's top executive.
In back-to-back conventions this past Saturday and Sunday, the government's Army-backed Social Democratic Party and the major opposition party, the Brazil Democratic Movement, freely chose their candidates to replace President Joao Baptista de Oliveira Figueiredo. The fifth general to rule Brazil since a 1964 coup, Figueiredo is to step down March 15.
His successor will not only be a civilian, but just possibly a member of the opposition, whose emboldened leaders, together with Social Democratic dissidents , are determined to beat the government party at its own electoral game.
Social Democratic nominee Paulo Salim Maluf will meet a formidable opposition candidate in Tancredo Neves, the governor of Minas Gerais State. The two will contest the presidency Jan. 15 in the Electoral College - a body the government party has successfully manipulated for 20 years.
But all this politicking has little to do with the Brazilian populace, which has not voted for president since 1960. Brazil's opposition parties failed to muster the two-thirds of Congress necessary to approve a constitutional amendment reestablishing the popular vote, and the Figueiredo government has insisted that only the successor of his successor will be chosen by a direct election.
Yet, despite its inching pace, the government's program of abertura, or political opening, was exemplified by the weekend's political conventions. These conventions were the first in two decades to go off without interference by the military.
In Brazil's tight-lidded political system, public fests have long substituted for genuine political participation. But this time, the celebrations were for real.
The government party's convention hall was wrapped in electric-colored banners and hung with great pulsing neon marquees.
The opposition party convention fluttered with placards declaring everything from simple democracy to ''out with the IMF'' (International Monetary Fund). Even the capital's stately palms were swathed in brilliant campaign colors.
Frustrated earlier in their drive to reinstate the direct vote, the opposition parties audaciously decided to meet the government head-on in the Electoral College, which is still dominated by the Social Democrats.
The opposition candidate, Mr. Neves, was officially declared a challenger on Sunday in the Brazilian Democratic Movement's convention. The smallish, self-possessed governor has been planning for this political moment for most of the four decades of his political career. A former justice minister under the populist dictator Getulio Vargas and Brazil's first prime minister, Mr. Neves has been in the thick of virtually every crisis Brazil has passed through in the past 30 years.
A conciliator by nature and temperament, Neves negotiated Joao Goulart into the presidency in 1961, when President Janio Quadros resigned and the hard-line military was set against accepting his left-leaning vice-president. When the governing junta banned all political parties save ''official'' ones in 1965, Neves abandoned the conservative Social Democrats to join the opposition. Moderate in his methods, Neves nevertheless remained a staunch opposition leader throughout the tenure of the military government.
Cautious and tight-lipped, Neves is given to back-room huddles and closed-door meetings with impresarios and intellectuals of all political stripes. Yet he is a rousing speaker, and he had the entire congressional gallery responding thunderously to his 26-page acceptance speech on Sunday. Neves has pledged to pay Brazil's debt, but ''not under conditions that sacrifice our sovereignty.'' He has also vowed to charge Congress with the task of carrying out sweeping, democratic reforms in the Brazilian Constitution.
Paulo Maluf couldn't be more different. The son of a Lebanese immigrant, he does not hail from a pedigreed political family nor does he have military connections. A millionaire heir to a family fortune made in lumber, Maluf married into a wealthy Brazilian-Lebanese family. He has benefited from the closed political system of Brazil, winning appointed posts as mayor of Sao Paulo and later governor of that industrial state.
Yet Maluf stunned traditional Brazilian politicians twice: In 1978, when he stole away the party nomination for Sao Paulo governor from the government's own candidate. He did it again on Saturday, trouncing Interior Minister Mario Andreazza - Figueiredo's choice for the Social Democratic nominee - in the Social Democratic Party convention by the margin of 493 votes to Andreazza's 350 .
A glad-handing and generous-spending politician, Maluf has been criticized for his use of the public largess. (In one well-known case, he was ordered to repay the state for a gift of Volkswagen cars for each member of Brazil's World Cup Soccer team. Maluf insisted the money had come out of his own pocket.)
Often called an unpopular figure, Maluf counters sharply that in 1982 he won more votes than any other congressional candidate in Brazil. Nevertheless, he stiffly opposed all efforts to restore direct elections for the office he is vying for, the presidency.
Like Neves, Maluf has pledged not to sacrifice Brazilian development to debt payments and has promised to run the country as efficiently as a business executive.
Yet, while his supporters praise his efficiency, critics - including members of his own party - say his no-holds-barred drive for the presidential nomination has divided and subdivided the Social Democrats.
A precious bloc of some 55 to 60 congressional members, including Vice-President Aureliano Chaves, left the Social Democratic Party before the convention, pledging to support the opposition candidate. That bloc of votes, observers say, may just be enough to swing the election from the government party to the newly galvanized Brazilian opposition. But the Electoral College is still considered to be in the hands of the government.