At 2 in the morning, a crowd still chokes the intersection of this city's two stylish pedestrian avenues. These are businessmen, shoppers and passers-by, absorbed in the oratory of anonymous men and their arm-waving political arguments.

For blocks around, the tinny blasts of loudspeakers herald Argentina's national elections Sunday. Pamphlets carpet the pavements and banners droop over avenues where campaign caravans pass with blaring horns.

There is a sense that years of repression, war and economic paralysis may finally lead Argentina to anarchy. "This is the last chance," says a barrel-chested man in a rumpled suit and tie. "We are in a process of decomposition. If we have another failed government, another economic disaster, another military coup, then ciao. Nothing will be left."

That warning, delivered with the common hyperbole of politics in Buenos Aires, nevertheless captured the issue that has shaped Argentina's return to democracy. The first election campaign here in a decade has been rent by bitter partisan polarization, continually threatened by institutional breakdown, and set against a backdrop of hyperinflation and financial chaos.

The question, say many Argentines now, is not so much who will win Sunday's vote but whether any government can stabilize South America's most turbulent country.

"The country has lived through seven years of authoritarianism," said Italo Argentino Luder, the Peronist party presidential candidate and a slight favorite over Raul Alfonsin of the Radical Party, recently. "All of that has put us on the border of national dissolution."

Luder and Alfonsin have promised that this election will end Argentina's 55-year cycle of alternating military and civilian governments. The public and its political leaders, they say, have learned the value of democratic activity.

However, there are daily signs of the country's persistent social maladies. Mudslinging has taken the place of serious partisan debate..

The armed forces have split into dozens of factions, union leaders have been unable to control a wave of wildcat strikes, and one strong-minded provincial judge backed by hard-line military nearly forced a default this month on the country's $40 billion foreign debt. Violence, meanwhile, remains a constant factor.

Moreover, some analysts here say, neither typical Argentines nor their political leaders seem to have faced the reality of the country's situation. "What worries me is that we don't have any mature discussion of the problem of Argentina," said Roberto Cortes Conde, a leading historian and political scientist.

"The society has to realistically define what its possibilities are now," Cortes Conde said. "But I don't know if anyone is going to have the energy or the capacity or the courage to do it."

The elected president will inherit what Alfonsin calls "a mine field," charged by two immediate, dangerous issues: the battered economy and the legacy of military repression and political violence.

The economic situation is already worse than that which helped prompt the military's 1976 coup against the last civilian government. After a 10 percent decline in economic production in the last two years, Argentina is now afflicted by unemployment as high as 15 percent and the world's highest inflation.

The elected government will have to begin talks within 10 days after the election with the International Monetary Fund, because Argentina's financing plan for its foreign debt has collapsed since August. The national financial system has all but shut down.

Even more dangerous, however, may be the problem of addressing the military's human rights violations and the country's deep-rooted habits of political violence. The outgoing armed forces decreed an amnesty law last month seeking to halt investigations of their internal "dirty war" of torture and killings and the estimated 6,000 to 20,000 cases of abductions and disappearances. But in the last month, Argentine judges refused to apply the amnesty.

The new civilian government will face enormous pressure to investigate and try military leaders for human rights crimes. It will also have to act decisively to dismantle a still-existing network of death squads, paramilitary operatives and swollen military intelligence services. Any such action, however, could quickly lead to a confrontation with military leaders--and the possibility of another coup.