If Ko decides to run for the presidency, he will split votes from both the KMT and DPP.
Most polls show that Ko’s participation would have a bigger impact on Tsai. In the same TVBS polling result, both Han and Tsai would be able to gather over 90-percent of voter support from their respective party, but Tsai has a slight advantage with the median voters. However, if Ko competes in the race, he would snatch 39-percent of the median votes, most of which would be taken from Tsai.
Ko’s power lies in his appeal to the median voters, who would have a decisive influence in the 2020 presidential election. If he does declare to run, Tsai might likely be the first Taiwanese president to lose re-election.
Taiwan’s political atmosphere, however, has been changing drastically since the 2018 local elections. Everything that seemed impossible has become possible. And since Ko’s support base largely comes from the unpredictable median voters, it would be even harder to foresee the outcome.
Ko is unlikely to become president next year, but his real motive is to build his political network outside of Taipei. When his mayoral term ends in 2022, he will be more than qualified to run in the 2024 presidential election with a well-established team under his command.