The debate's actual impact on voter behavior appeared modest.
In the weeks before Peru's June presidential runoff, the distance between two visions of the country — one rooted in the urban capital, the other in the rural interior — narrowed to five percentage points. A Datum poll placed Pedro Castillo at 41 percent and Keiko Fujimori at 36 percent, a shift that fell within the margin of error yet signaled a race still very much alive. Geography, hidden preferences, and a large undecided electorate reminded observers that in deeply divided societies, polls measure not just intention but the difficulty of knowing one's own mind.
- Fujimori gained two points and Castillo lost two since late April, tightening a race that had seemed more settled just weeks before.
- The May 1 debate in Cajamarca gave Fujimori a perceived edge — 44 percent said she won — yet 88 percent of voters reported their choice was entirely unchanged by the exchange.
- A striking 42 percent of the electorate remained undecided, and both candidates faced a 'hidden vote' of supporters unwilling to declare themselves openly to pollsters.
- Commitment levels revealed asymmetry: 74 percent of Castillo voters were firm in their choice, compared to 67 percent of Fujimori supporters, leaving meaningful room for late movement.
- The northern regions of Peru, carrying significant electoral weight, emerged as the likely battleground that could tip the final outcome either way.
Peru's presidential runoff entered its final stretch with the gap between the two candidates narrowing to five points. A Datum poll conducted in early May showed Pedro Castillo of Perú Libre at 41 percent and Keiko Fujimori of Fuerza Popular at 36 percent — a four-point shift since late April that, while statistically within the margin of error, suggested a contest far from settled.
The candidates had met for their first debate on May 1 in Cajamarca, held outdoors under COVID-19 restrictions. Voters gave Fujimori the edge — 44 percent to Castillo's 32 percent — but the event moved few minds. Only 4 percent said they changed their vote afterward, and 88 percent reported their intention was unchanged. The debate shaped perceptions more than it redirected ballots.
Datum director Urbi Torrado urged caution in interpreting the movement, noting that 42 percent of the electorate remained undecided and that both camps harbored a 'hidden vote' — supporters reluctant to reveal their preference to pollsters. Commitment levels differed: 74 percent of Castillo's voters were firm, versus 67 percent of Fujimori's. Even the 11 percent planning to cast blank or spoiled ballots showed uncertainty, with nearly half still weighing the option.
The contest's geography loomed large. Fujimori led in Lima while Castillo dominated the interior, particularly the east and north. Torrado pointed to the northern regions — and their electoral weight — as potentially decisive. With weeks remaining and the electorate still in motion, the survey captured a country genuinely uncertain about its direction.
The race for Peru's presidency tightened in the final weeks before the June runoff. A Datum poll released in early May showed Keiko Fujimori, the Fuerza Popular candidate, trailing Pedro Castillo of Perú Libre by five percentage points—36 percent to 41 percent. The gap had narrowed since late April, when Fujimori gained two points while Castillo lost two, though the polling firm noted the shift fell within the survey's 2.8 percent margin of error.
The movement came after the candidates' first debate on May 1 in Cajamarca, held in an open-air venue with limited attendance due to COVID-19 restrictions. Fujimori was seen as the debate winner by 44 percent of voters surveyed, compared to 32 percent who believed Castillo prevailed, with 20 percent calling it even. Yet the debate's actual impact on voter behavior appeared modest. Only 4 percent of respondents said they had changed their vote after watching the exchange, concentrated in Lima and the northern regions. Another 8 percent said they were reconsidering their choice. The vast majority—88 percent—reported their voting intention remained unchanged.
Urbi Torrado, the director of Datum, cautioned against reading too much into the recent movement. She told RPP Noticias that the four-point shift in the electorate, with roughly half moving toward Fujimori, was statistically unremarkable given the margin of error. She also noted a significant layer of uncertainty in the electorate: 42 percent remained entirely undecided, and both candidates faced what she called a "hidden vote"—supporters reluctant to admit their preference to pollsters, making the true distribution of support difficult to measure.
Commitment levels differed between the two camps. Among Castillo voters, 74 percent said their choice was firm. Among Fujimori supporters, 67 percent expressed certainty. Those planning to cast blank or spoiled ballots—11 percent of the sample—showed the most fluidity: 46 percent were still evaluating the option, while 24 percent were resolved to do so when they voted on June 6.
Geography appeared to be shaping the contest in ways that could prove decisive. Fujimori held a clear advantage in Lima, the capital and the country's largest urban center. Castillo led in nearly every interior region, with particularly strong support in the east and north. Torrado suggested that the northern vote, given its electoral weight, might ultimately determine who would be Peru's next president. The Datum survey, conducted May 5-6 among 1,203 respondents nationwide with a 95 percent confidence level, captured a race still very much in motion with weeks remaining before voters would decide.
Notable Quotes
The movement is within the margin of error and cannot be said to indicate a clear trend in either direction.— Urbi Torrado, director of Datum polling
The northern vote, given its electoral weight, may ultimately determine who becomes Peru's next president.— Urbi Torrado, director of Datum polling
The Hearth Conversation Another angle on the story
Five points is a real gap, but it sounds like it could evaporate. What's actually moving?
The honest answer is we don't know yet. The pollster herself said the recent shift is within the margin of error. It could be real momentum, or it could be noise.
But Fujimori won the debate by a wide margin—44 to 32. Shouldn't that translate to votes?
You'd think so. But 88 percent of people said the debate didn't change their mind at all. Only 4 percent actually switched. A debate win doesn't automatically become a vote win.
So what's the actual uncertainty here?
There's a lot. Forty-two percent of voters are completely undecided. And both candidates have what the pollster calls a "hidden vote"—people who won't admit to pollsters they support them. That's hard to measure.
Where does Castillo's strength come from?
The interior. He dominates almost everywhere outside Lima. The north especially. And the pollster thinks the north might decide the whole election.
Why would the north be decisive?
Electoral weight. It's a large enough region that if it breaks decisively one way, it could overcome Fujimori's advantage in Lima. That's the real battleground.
So this is still genuinely open?
Completely. You have undecided voters, hidden voters, and a five-point margin that could shift either way. Nothing is settled.