Polls show a statistical tie between Humala and Ms. Fujimori, the daughter of jailed former President Alberto Fujimori. Both candidates count many detractors, but it is more for their political baggage than for their policy positions.
Fujimori's father, whose presidency collapsed amid human rights allegations including the use of death squads, looms over her campaign, prompting many Peruvians to ask what justice would look like under her leadership.
Humala, an ex-Army officer and nationalist, remains a wild card for many. He hasn't shed his hard-core leftist reputation among the business set: After the first round of voting in April that put him out front, Peruvian markets plunged. But he says he has no intention of repeating the "Venezuela model" in Peru, even though he promised to share economic prosperity with the poor one-third of Peruvians left behind amid 9 percent growth last year. Some of his positions today are even to the right of Fujimori, says Mr. Alvarez Rodrich. "This is not a contest between the right and left," he says.