BUENOS AIRES - After a period when South American regimes seemed untouchable, the forces of opposition have revived in Argentina, Brazil, and Venezuela.

Up until a few months ago, South American presidents seemed invincible. They were reelected automatically. If someone faced a term limit, a successor would be designated who would later achieve a crushing, electoral victory. The opposition would be left disheartened and fragmented. As a result, the Argentinian “radicals,” Brazilian “tucanos,” and Venezuelan “escualidos” (nicknames given to the opposition movements) all shared the same fate: political impotence and electoral defeat.

Then, all of a sudden, something changed. Today in Argentina, supporters of President Cristina Kirchner have not found a suitable candidate to succeed her. In Brazil, the Workers’ Party has threatened President Dilma Rousseff with dusting off former President Lula’s candidacy in order to reverse the economic slowdown. In Venezuela, polls show Henrique Capriles gaining ground over President Nicolas Maduro just weeks after having narrowly lost the election.

What happened?

There are three possible answers: a deterioration in governmental management, a stronger opposition strategy, or a change in the international context.

In all three countries, the situation has worsened. Simultaneously, after a decade of high growth and overcoming the global crisis of 2009, the economy slowed down last year and now tends towards stagnation.

In Brazil, they speak ironically of the “pibinho” (“little GDP”) referring to the minute increase in gross domestic product, which clawed 0.9% in 2012. In Argentina, investment and consumption are receding. In Venezuela, the revolution has to import tons of toilet paper. At the same time, inflation exceeded 6.5% in Brazil and reached 30% in the other two countries.

Meanwhile, the oppositions’ strategies have improved. In all three countries, the government cornered the opposition labeling it “neoliberal” and denigrating its legacy. Neither the Argentinian radicals nor the Brazilian social-democrats nor Venezuelan civil society were comfortable in this corner. A generational change and the emergence of leaders like Ernesto Sanz, Aecio Neves, and Henrique Capriles helped change the political landscape.

Favorable conditions for reelection have run out

It remains to be seen whether Sanz and Neves will achieve Capriles’ feat. He managed to bring most of the opposition together in order to establish himself as a viable alternative.

In Argentina, the Radical Civic Union has been building strong political alliances in big provinces such as Cordoba, Santa Fe, and Mendoza, but it still runs third in Buenos Aires behind Peronist alternatives.

In Brazil, Fernando Henrique Cardoso’s Brazilian Social Democracy Party must manage two conflicts. First, it must handle a process of succession in which the founding generation faces the renewing one. Second, in terms of ideology, the leadership’s progressivism has to work with a conservative electoral base.

In Venezuela, the political scene is clearer. If, as allowed by the constitution, a recall referendum – to determine whether Maduro should stay in office – took place in the near future, Maduro would lose his seat to Capriles.

The third explanation ignores both the government and the opposition while focusing on the international context. In a recent study, Brazilian political scientists Daniela Campello from Princeton University and Cesar Zucco from Rutgers University analyzed international determinants of presidential performance in Latin America. In their paper, entitled Merit or Luck, they identified the determining factors when it comes to predicting presidential success. They came to a distressing conclusion: in Latin America, voters reward or punish their presidents for reasons beyond governmental management.

The study reveals that it is possible to predict presidential success without resorting to domestic economic factors, but only based on the price of commodities and international interest rates. Thus, if projections for European recession and waning Chinese growth are confirmed, favorable conditions for reelection from the past decade in South America will have run out.

The return of political will was convincing while the tailwind lasted. However, the region still navigates with the wind in its favor, for now. It is crossing a grey area, a period of transition charged with uncertainty in which political virtue has its chance. For governments, the challenge is to maintain the support of vulnerable sectors without jeopardizing the macroeconomic stability. For the opposition, the challenge is to unite the troops and, above all, offer a credible programatic alternative. The race is on.