OCTA Research's latest 2028 Presidential Political Map showed a geographically divided electorate, with Vice President Sara Duterte maintaining overwhelming support in Mindanao and leading in the Visayas, while former vice president and Naga City mayor Leni Robredo continued to dominate most parts of Luzon in a hypothetical presidential contest.
The political map is based on OCTA's Q2 2026 Tugon ng Masa (TNM) national survey, conducted from July 4 to 11 through face-to-face interviews with 1,200 adult Filipinos.
The survey found Duterte leading Robredo, 43 percent to 34 percent, while 23 percent of respondents said they were undecided, refused to answer, or favored neither candidate.
Compared with the first quarter survey, Duterte's voter preference declined by three percentage points from 46 percent, while Robredo's support slipped by one point from 35 percent. The share of undecided respondents rose from 19 percent to 23 percent.
The regional breakdown highlighted stark differences in voter preference across the country.
Mindanao remained Duterte's strongest base, with 76 percent support against Robredo's 6 percent. Eighteen percent of respondents in the region were undecided.
Duterte also led in Visayas with 51 percent, nearly double Robredo's 26 percent, while 23 percent remained undecided.
Robredo, meanwhile, continued to dominate Luzon. In Northern Luzon, she garnered 59 percent support, compared with Duterte's 18 percent, while 23 percent of respondents were undecided.
She also posted a commanding lead in Southern Luzon, where she received 52 percent support against Duterte's 34 percent. Fourteen percent of respondents in the region remained undecided.
Metro Manila was the most competitive battleground, with Duterte and Robredo tied at 34 percent each. The National Capital Region also recorded one of the highest shares of undecided voters at 32 percent.
The political map also showed that Robredo's strongest areas were concentrated across Luzon, while Duterte's support remained concentrated in Visayas and particularly in Mindanao, underscoring the country's continuing regional political divide.
Despite Duterte's nine-point national advantage, the survey indicated that nearly one in four respondents have yet to choose a candidate, suggesting voter preferences remain fluid more than a year before the campaign period for the 2028 elections.
OCTA said the findings represent a snapshot of current public opinion rather than a forecast of the election outcome, noting that candidate decisions, political alliances, campaign developments and emerging national issues could still significantly reshape voter preferences.
The survey used probability sampling and has a national margin of error of ±3 percentage points at the 95-percent confidence level. Figures may not total 100 percent because of rounding.
