Vasquez also pointed to lackluster GDP growth over the last decade and rampant government corruption as factors that could leave the door open for a centrist opposition candidate like the Social Democracy Party's Aecio Neves.
A Rousseff defeat would be good news in the eyes of Brazil's business community, Spiro said.
"The equity markets in particular would like to see the back of Dilma Rousseff," said Spiro. "A win by Rousseff is a continuation of the status quo, and the status quo has been a failure. Brazil's economy has slowed to a crawl, it's flirting with recession, and interest rates are in double figures."
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Harold Trinkunas, a senior fellow at the Brookings Institute, said that while Rousseff's administration has been delaying tough economic reforms in the run-up to this year's election, they will have to be made soon.
"The government's going to have to make some adjustments to the currency, which has been quite strong and hurting exports, and address the high cost of living domestically, the high cost of imports, and expansion of consumer credit to quite high levels," Trinkunas said. "They have a lot of issues to deal with."