Agência Senado / CC BY 2.0

Q: President Dilma Rousseff and challenger Aécio Neves emerged Sunday as the top vote-getters in the first round of Brazil's presidential election and now head to an Oct. 26 runoff. The results ended the campaign of Marina Silva, who finished third. What were the reasons behind Neves' comeback and Silva's defeat? What factors will influence the election between now and the second round? Which candidate will come out on top?

A: Peter Hakim, member of the Advisor board and president emeritus of the Inter-American Dialogue: "In two weeks, Aécio has lifted his vote from 20 percent to a high of 34 percent. Dilma, in the last few days, has dropped around six points. Aécio has the momentum. He performed exceptionally in the last debate, demonstrating a readiness for the presidency. Marina has implied that she supports Aécio. Even without a formal endorsement, he will certainly grab the lion's share of her vote. To win, he needs 60 to 70 percent, doable--but just barely. Besides an 8 point lead, Dilma has other advantages--including a highly professional campaign team. They know her weaknesses and Aécio's and will do whatever is necessary to work around the former and brutally attack the latter--as they did to Marina. Lula remains a crucial asset for Dilma. Dilma, moreover, has mastered the narrative that she has to communicate to gain re-election. Brazilians, especially lower income groups, should be careful not to vote for someone who will erase the economic and social gains achieved during 12 years of Workers' Party (PT) government. That message did in Marina, and it will be central to the campaign against Aécio. His challenge is difficult. Aécio must rebut the charge that he will turn back the clock, attack Dilma without criticizing the ever-popular Lula and offer a plan to govern that inspires voters. Adding up the assets and liabilities suggests that Dilma should win this election, but the game is not over. Dilma is vulnerable on the economy, PT corruption, and the continuing mediocrity of public services. Four debates give Aécio the time to demonstrate his political skills. Neither Dilma nor Aécio has yet built an emotional bond with voters. After four years, it is probably too late for Dilma. Aécio has three more weeks."

A: Carlos Eduardo Lins da Silva, global fellow at the Woodrow Wilson International Center for Scholars: "President Dilma Rousseff got 43 million votes out of the 142 million registered voters in Brazil in the first round of the election. This means that nearly 100 million voters chose not to cast their ballots for her. It is true that 29 percent of registered voters did not vote for any of her opponents: 27.7 million did not turn out although voting is compulsory (they will pay a small fine), and 11 million either cast a blank vote or nullified it. Rousseff got almost 42 percent of the valid votes (43.2 million) and Aécio Neves of the Social Democracy Party (PSDB), almost 34 percent of them (34.9 million). This is the smallest percentage for a PT candidate in the first round of a presidential election since 2002. Also, it is the smallest difference between the PT and the PSDB in the same period of time. According to the latest polls, 59 percent of the 22 million who voted for Marina Silva on Sunday said they would pick Neves in a runoff if she did not qualify. This would mean around 13 million ballots, enough to fill the gap of around 8 million ballots between Rousseff and Neves. Does this mean that Neves will be elected on Oct. 26? No way. In this totally unpredictable race, Brazilians have been tricking pundits, pollsters, consultants, journalists and politicians again and again. One month ago, Neves had 14 percent support among likely voters. He more than doubled that. Neves' support may grow even more until he wins in a landslide, or he may dehydrate as did Silva, the frontrunner in early September. Let's wait and see."

A: Riordan Roett, director of the Latin American Studies program at the Johns Hopkins School of Advanced International Studies: "Sunday's election was full of surprises. Receiving just 41 percent of the votes cast, Dilma Rousseff did far more poorly than most of the polls predicted. Marina Silva of the Socialist Party was the favorite of the opposition, until she wasn't, and ended her presidential campaign with 21 percent of the ballots cast--barely better than her showing four years ago. And Aécio Neves of the PSDB, who was seen as a 'has been' in the race just a short time ago, is now the candidate with a strong possibility of defeating Dilma in the second round. Silva suffered from the unscrupulous campaigning of the PT during the campaign and by those voters who may have perceived her as not ready for the presidency. Rousseff's support was mediocre because of a sense that the economy is in trouble and she may not know how to fix it-or may not want to do so for ideological reasons. Neves pushed past Silva because he kept raising issues that are on the minds of many Brazilians-rising inflation, very low growth, high prices and a perception that the PT isn't serious about addressing shortfalls in education and public health. The question is will Silva voters vote for Neves? He will have equal TV time in the second round which should work in his favor. The PSDB carried the state governorship in São Paulo, an important source of votes, but lost in Neves' home state, Minas Gerais. He will need to fortify his support at home and build on the widespread popularity of the PSDB in the center-west, south and southeast."

A: Richard Feinberg, professor of international political economy at the University of California at San Diego and former president of the Inter-American Dialogue: "The numbers tell us that Aécio Neves will need to attract about 70 percent of Marina Silva's first-round votes to overcome Dilma Rousseff's commanding first-round lead. Neves could manage this leap either by continuing to concentrate on southern cities, building his lead among the emerging middle classes and cutting into PT strongholds among the poor, or else trying to reduce Dilma's majorities in her northern strongholds. Either way, it's a tall order. But Neves has some momentum and the probable endorsement of Silva. Looking ahead, while the campaigns have focused on domestic issues, the biggest impact of a Neves upset could be on foreign policy. Dilma encapsulates the baby-boomer generation that suffered under military rule, and carries some anti-U.S. resentments from those searing experiences. In contrast, a leading Neves foreign policy advisor, Rubens Barbosa, a former Brazilian ambassador in London and Washington, in his new memoir, decries the PT's foreign policies as being destructively partisan and ideological, confused as to fundamental purposes and undecided as to just what it hopes to attain in its relations with the United States. A Neves administration would seek to repair relations with Washington and, especially if joined by a more pragmatic government in Buenos Aires, could breathe new life into inter-American relations."