Oh Se-hoon of the main opposition People Power Party (PPP) defeated Park Young-sun of the DP, 57.5% to 39%, to become Seoul’s mayor. The constitution of the DP stipulates that “a candidate shall not be nominated if an elected official belonging to the party loses his or her position due to a grave error and a by-election is held.” But the party’s members voted to abolish this provision and presented candidates for the by-election. These elections were held due to sexual harassment scandals involving these two mayors, both belonging to the DP. However, the DP’s winning streak stopped on April 7, 2021, with the mayoral by-elections in Seoul and Busan. The party won 163 of the 300 seats in the 2020 general election the main opposition United Future Party took 84 seats ( Hahm 2021: 69). It continued its victorious streak in the 2018 local elections and the 2020 general election. The Democratic Party (DP) leaped forward as the largest party in the 2016 general election and then took off as the ruling party with Moon Jae-in’s victory in the 2017 presidential election.
