Andres Oppenheimer

Andres Oppenheimer: A new day in Latin America?

Here’s a scenario that seemed highly unlikely only a few weeks ago, but that has a 50 percent chance of happening in light of the political earthquakes that are rocking Argentina, Brazil and Venezuela, and that could mark the end of a 15-year-old leftist populist cycle in South America.

It would go like this:

Argentina’s center-right opposition leader Mauricio Macri, bolstered by his unexpectedly strong performance in the Oct. 25 first-round presidential elections, wins the Nov. 22 runoff elections. Macri would lure an avalanche of foreign investments and spur hopes of a dramatic economic recovery after several years of economic downturn.

An open critic of populist authoritarian regimes, Macri has said that if elected, he would demand that Venezuela abide by regional commitments to democratic rule. His election would make big headlines everywhere, and turn him into an important regional figure.

(A milder version of this scenario would take place in the event of a victory by Argentina’s government-backed candidate Daniel Scioli. He is more moderate than outgoing president Cristina Fernández de Kirchner, and would not be as close to Venezuela as she is.)

Meanwhile, in Brazil, prosecutors might link beleaguered President Dilma Rousseff, whose popularity has sunk to 9 percent, to the Petrobras oil company corruption scandal. Congress might decide to impeach her, and the country would plunge into a constitutional succession, or early presidential elections. Brazil would shift toward more market-friendly economic policies, and take greater distance from Venezuela and its leftist allies.

(A less dramatic version of this scenario would be if Rousseff decided to weather the storm by convening a “national unity” government with opposition parties to remain in office during the remainder of her term.)

These major changes in South America’s political map would have a major impact on Venezuela’s key Dec. 6 legislative elections. They would deprive Venezuelan President Nicolás Maduro from the support of the region’s biggest countries if he decided to rig the vote. With the economy shrinking by 8 percent this year, a 200 percent inflation rate — the world’s highest — and widespread food shortages, Maduro’s party would almost surely lose a free election, pollsters say.

In recent Venezuelan elections, Brazil and Argentina had immediately accepted official results, which were disputed by Venezuela’s opposition. That may not happen this time around.

Maduro, who has refused to allow electoral observers from the European Union or Organization of American States, could call for an urgent presidential summit of UNASUR, an Ecuador-based South American group that has often supported him, to validate a rigged election result on election night. He could still count with Argentina’s outgoing president Fernández, whose term expires Dec. 10.

But moderate UNASUR members, such as Chile and Colombia, would most likely schedule such a meeting for after Dec. 10, once the outgoing Argentine president is out of the picture. Without unconditional support from Argentina and with a skeptical Brazil — whose electoral tribunal has already announced that it will not send electoral observers to Venezuela because of concerns over that country’s electoral process — the Venezuelan government would only count with the support of smaller allies such as Bolivia, Ecuador and Nicaragua.

If Maduro’s party loses the Dec. 6 election and he refuses to concede, there could be enough consensus within the OAS to invoke the group’s Democratic Charter, which calls for the collective defense of democracy in the region.

Diego R. Guelar, head of Macri’s party’s international relations office, told me that a Macri administration would not validate a fraudulent election in Venezuela. Furthermore, it would seek to team up with Brazil to sign a free-trade deal with the European Union and the Pacific Alliance made up of Mexico, Colombia, Peru and Chile.

Macri’s election “would mark a significant regional shift, and end of our region’s isolation from the world’s biggest trading blocs,” Guelar said.

My opinion: An opposition victory in Argentina’s runoff vote would change Latin America’s political map, ending 15 years of corrupt leftist populist governments that have left their countries bankrupt. I’m not yet willing to bet that this regional scenario will come true, but there’s an even chance that it will.

Andrés Oppenheimer: Twitter: @oppenheimera; Watch “Oppenheimer Presenta” Sundays at 9 p.m. on CNN en Español

Watch “Oppenheimer Presenta” Sundays at 9 p.m. on CNN en Español