The Seoul election that South Korea won and lost at the same time

    TOKYO — South Korea’s June 3 local elections were supposed to be simple. President Lee Jae-myung, one year into his term, sought a popular mandate. The opposition, still reeling from former President Yoon Suk Yeol‘s botched martial law declaration in late 2024 and his subsequent impeachment, was supposed to crumble. And by one measure, it did. The ruling Democratic Party of Korea (DPK) won 12 of 16 metropolitan mayoral and gubernatorial races — a landslide by any conventional standard. The party captured Busan, a conservative stronghold, for the first time in eight years. It swept 17 of Seoul’s 25 district chief posts. On paper, President Lee returned to Tokyo’s Nerima district — where I grew up in the shadow of a modest Shinto shrine — with the kind of consolidated power that would make any Japanese prime minister envious.

    But numbers lie. Or rather, they tell only part of the story.

    The real headline of this election lies in what the ruling party lost, not what it won. Seoul, the capital, eluded the DPK‘s grasp once again. Incumbent Mayor Oh Se-hoon, a conservative, secured a historic fifth term by the slimmest of margins: 49.15 percent to 48.13 percent, a gap of just 0.6 percentage points. The DPK had led for most of the counting. Exit polls had projected a comfortable DPK victory, with the party‘s Chong Won-o leading by 5.4 percentage points. Those projections unraveled dramatically in the early hours of June 4. And in the 14 parliamentary by-elections held the same day, the ruling party actually lost four seats it had previously controlled. A ruling party that swept nationwide yet lost the capital is like a sumo wrestler who pins his opponent but falls out of the ring himself. The win is there. So is the injury.

    From Tokyo, where we have watched democratic transitions across Asia with a mixture of admiration and anxiety, this Korean election offers a cautionary tale about the nature of political power in an age of permanent polarization. A mandate, as The Korea Herald aptly noted, is less a blank check than a mortgage — granting power today while billing governments later. And the bill for the DPK‘s incomplete victory is already arriving.

    A victory that felt like defeat

    What makes this election so psychologically complex is the dissonance between its aggregate numbers and its symbolic wounds. The DPK won 12 of 16 top regional posts. It captured 119 of 227 lower-tier local government heads. It won nine of 14 parliamentary by-elections. But ask any DPK insider privately, and they will tell you: this did not feel like a victory party. Party chair Jung Chung-rae, in a tone far more subdued than the numbers warranted, thanked voters for “a great nationwide victory” while conceding that “it hurts we could not reclaim Seoul”.

    The Korean press has described the result as a “victory with brakes applied.” And for good reason.

    Consider what did not happen. The DPK failed to unseat Oh Se-hoon despite President Lee‘s approval rating hovering around 60 percent. It failed to capture Daegu, the heart of conservative territory — though even there, the DPK made unprecedented inroads at the local council level, a sign that the conservative fortress is cracking. And in Busan‘s Buk-A district, the most closely watched parliamentary by-election, former conservative leader Han Dong-hoon — running as an independent after being expelled from the People Power Party (PPP) — defeated Ha Jung-woo, an artificial intelligence expert personally handpicked by President Lee. A loss like that is not just a loss. It is a public repudiation of presidential judgment.

    For a Japanese observer, this feels painfully familiar. We, too, have watched ruling parties claim victory while bleeding support in symbolic contests. The difference is that in Japan‘s parliamentary system, a loss in Tokyo’s gubernatorial election would trigger immediate leadership reviews. In South Korea‘s hyper-presidential system, President Lee remains securely in office until 2030. But the political toll is already visible.

    The youth have moved

    Perhaps the most significant signal buried in these results concerns South Korea’s younger voters, the so-called 2030 generation. For years, this cohort was assumed to lean progressive — the heirs to the Candlelight Revolution that brought down Park Geun-hye. The June 3 elections suggest a dramatic realignment.

    In Seoul‘s Gwanak District, long considered a reliable DPK stronghold, a closer look at the vote by neighborhood reveals a striking divergence. In areas near subway stations with high concentrations of people in their 20s and 30s — young office workers living in officetels and new housing — the DPK‘s candidate either lost or barely scraped by. In Nakseongdae-dong, for example, Oh Se-hoon narrowly outpolled the DPK candidate. By contrast, in the district‘s traditional low-rise residential areas where those aged 50 and older make up nearly half the population, the DPK won by double-digit margins.

    What explains this? Housing prices, above all. During President Lee’s first year in office, apartment values surged by double digits across much of Seoul — by more than 20 percent in some eastern districts. For young Koreans already struggling to enter a brutal job market and facing the world‘s lowest fertility rate, rising real estate is not prosperity. It is a closing door. A 25-year-old college student who moved up from Gwangju told a Korean newspaper: “There’s a perception that the Democratic Party has failed to solve problems as housing prices have surged and finding a job has become difficult. On real estate and jobs, more friends actually sympathize with the conservative camp‘s arguments”. A 30-year-old female voter who had always voted for the DPK said she chose Oh Se-hoon for the first time.

    If this trend continues, South Korea’s progressive camp faces a demographic time bomb. Its aging base remains loyal; its young base is slipping away.

    The opposition’s hollow survival

    The People Power Party should be celebrating. It held Seoul. It held Daegu. It prevented a complete wipeout. But here, too, the victory is hollow.

    The PPP won just four of 16 mayoral and gubernatorial contests. That is down from the 12 it captured in the 2022 local elections. Its internal divisions remain gaping. Former President Yoon‘s shadow — the December 2024 martial law declaration that led to his impeachment — continues to haunt the party. Voter turnout reached 61.0 percent, the highest for a local election since 1995. Much of that energy was less about enthusiasm for the PPP than about fear of one-party dominance. Voters showed up to check the ruling party, not to embrace the opposition.

    Seoul Mayor Oh Se-hoon, the PPP‘s sole survivor of any national stature, has already begun distancing himself from his party’s leadership. In a striking interview after the election, he warned that the PPP risked degenerating into a “YouTube party” that “only scratches the itches of hardcore supporters”. He called on the party to embrace a centrist shift. The subtext is unmistakable: Oh is preparing for a presidential run in 2030, and he does not want to be dragged down by a party that refuses to learn from its defeats.

    Meanwhile, the PPP‘s chairman, Jang Dong-hyuk, faces growing calls for his resignation. But neither he nor his critics seem to have a clear answer to the party’s existential question: What does conservatism stand for in South Korea today beyond opposition to the ruling party?

    The dangers of omnipotence

    From Japan, the most unsettling aspect of this election is not what it says about South Korea‘s political parties, but what it says about the structure of South Korean democracy itself.

    The DPK now holds the presidency, a majority in the 300-member National Assembly, 12 of 16 metropolitan mayorships, 119 of 227 lower-level local government heads, and 17 of 25 district chief posts in Seoul. That is an extraordinary concentration of political power in a democracy that only formally emerged from authoritarian rule in 1987. As The Korea Herald noted, the election “stripped away many of the political excuses governments typically enjoy”. There is no opposition-controlled legislature to blame. No obstinate local governments to resist. No checks except the constitutional court and public opinion.

    And yet, as the scholar Lee Hyun-chool told The Korea Times, voters appear to have exercised a balancing instinct: “When they feel both central and local powers risk becoming too concentrated, voters tend to step in to restore equilibrium”. That is precisely what happened in Seoul. The DPK‘s failure to capture the capital was not necessarily a rejection of President Lee’s policies writ large. It was a signal that Koreans still want some part of their political system to remain outside the ruling party‘s grip.

    Whether the DPK leadership understands that signal is another question. In the days following the election, the party leadership offered no apology and no strategic overhaul. “Even in victory, it is not truly victory,” a Chosun Ilbo columnist observed. That kind of complacency — mistaking a damaged win for a mandate — is precisely what has undone dominant parties in other democracies.

    A final view from Tokyo

    South Korea has entered a rare two-year period without a nationwide election before the next parliamentary vote in 2028. For the Lee administration, this is an opportunity: two years to implement economic reforms, address housing affordability, and manage a volatile geopolitical environment that includes North Korea‘s nuclear provocations and intensifying U.S.-China competition. For the opposition, it is a long, cold spell: two years to rebuild without the oxygen of a national campaign.

    What Japan has learned — through our own “lost decades” of economic stagnation and political churn — is that consolidated power does not guarantee good governance. On the contrary, it often breeds arrogance, insularity, and policy paralysis. The Lee government spent its first year defining ambitions. Its second will be judged by execution. Economic polarization, slowing potential growth, and labor-market rigidities will not be solved by slogans about past injustices. They require hard choices about real estate taxes, labor reforms, and fiscal consolidation — choices that will alienate parts of the ruling coalition.

    The voters who gave the DPK 12 governorships were not endorsing permanent one-party rule. They were demanding results. And as the Korea Herald‘s metaphor reminds us, political mortgages eventually come due. South Korea’s democratic health depends on whether President Lee uses his power wisely or squanders it in the belief that he has won something that he has not.

    Because from this side of the East Sea — or the Sea of Japan, depending on your map — a ruling party that wins everywhere except the capital is not a party with a mandate. It is a party on notice.