South Korea's Politics After Impeachment

Jinwan Park is a nonresident James A. Kelly Korea Fellow at Pacific Forum and a nonresident fellow at the European Centre for North Korean Studies at the University of Vienna.

At 11:22 a.m. on April 4, 122 days following the declaration of martial law, the Constitutional Court of the Republic of Korea rendered its verdict upholding the National Assembly’s impeachment motion against President Yoon Suk Yeol, effectively removing him from office. As political parties recalibrate their strategies in this new environment, Acting President Han Duck-soo leads the nation until the presidential election scheduled for June 3.

Reactions to the Court’s Decision

Approximately two hours following the Constitutional Court’s announcement, President Yoon issued a statement through his lawyers expressing appreciation to those who had “supported and cheered” him and described his presidential service as an honor to the nation and its citizens. Notably absent from this statement was any acknowledgment of the Constitutional Court’s ruling or any apologetic mention regarding the domestic and international crisis triggered by his martial law declaration, though he refrained from publicly contesting the verdict.

The main opposition Democratic Party of Korea (DPK) welcomed the Constitutional Court’s decision with measured enthusiasm. Party leader Lee Jae-myung praised Korean citizens for their role in preserving democratic institutions and pledged to serve as a beacon of hope. The party manifested notable restraint in its use of narratives, refraining from ad hominem criticism and excessive emotional displays, a stance seemingly calibrated with the upcoming presidential election in mind.

The ruling People’s Power Party (PPP), which mostly sided with President Yoon throughout this process, initially responded with disappointment, with several legislators privately criticizing the Constitutional Court’s verdict. However, PPP leader Kwon Young-se, a former Minister of Unification, swiftly issued a more nuanced statement affirming the party’s respect for the court’s decision to preserve democratic institutions and legal norms, despite disagreements.

The Main Opposition’s Advantages and Challenges

Yoon’s removal undoubtedly benefits the DPK and its leader, Lee Jae-myung, who lost to Yoon by less than one percentage point in the 2022 election. Recent poll results by Gallup and RealMeter demonstrate public sentiment favoring the opposition, with more than half of respondents (52 percent and 56.9 percent, respectively) preferring an opposition victory in the upcoming election. Lee leads among potential candidates significantly, though two-way surveys with potential conservative candidates indicate tighter races.

Lee’s recent acquittal of election law violation charges in the appellate court, overturning the lower court decision, also strengthens his position. At the same time, he still faces four other criminal investigations as well as the potential Supreme Court ruling. However, the Supreme Court’s ruling on his case will likely come after the June election, as such decisions typically take several months, and there’s significant political pressure on the judiciary to resolve the matter before the presidential race.

Despite these advantages, the DPK must recognize that its recent electoral successes in the recent by-elections and the 2024 general election stemmed largely from anti-Yoon sentiment rather than genuine enthusiasm for the party itself. The DPK’s campaign during these elections focused primarily on presidential scandals and public skepticism of his domestic policies and character rather than articulating a positive vision.

Developing and communicating a clear governance philosophy beyond mere anti-PPP rhetoric is important not only for winning the upcoming election but also for establishing public legitimacy that could prevent similar domestic turmoil in the future.

The Conservative Dilemma

With President Yoon’s fallout, the conservative PPP now faces a difficult balancing act between distancing itself from Yoon’s administration to appeal to independent voters and maintaining fidelity to his legacy to preserve core constituent support.

Notably, the PPP’s support has increased from the low-20s to the high-30s since December, largely through mobilizing hardcore supporters who believed in Yoon’s innocence and opposed the DPK’s strategy of continuously impeaching the acting presidents. This coincided with the rising popularity of cabinet members, including former Minister of Employment and Labor Kim Moon-soo, who remained loyal to the president and defended the martial law declaration.

With this, Yoon’s impeachment presents the PPP with a strategic choice to either continue prioritizing core supporters who remain central to their current political survival or pivot toward independents with more moderate rhetoric for electoral success. Recent electoral defeats and the proven importance of independent voters in determining election outcomes in the history of Korean politics may push the party toward centrism.

If the PPP eventually decides to pivot, the upcoming party primary presents an opportunity to present a vision distinct from Yoon’s legacy. Notable center-right figures like former PPP leader Han Dong-hoon and lawmaker Ahn Cheol-soo are expected to compete, and the fierce contest among approximately ten candidates will likely attract significant public attention—for better or worse—a notable contrast to the Democratic Party’s situation. The weighting of party member votes versus general public surveys in the primary will signal which direction the party intends to pursue.

Prospects for a Third Force Resurgence?

The emergence of a viable “third force” to challenge the two-party dominance appears unlikely given the limited timeframe and absence of compelling new political figures to mobilize independent voters and defectors from the two parties. Although approximately one-fifth of Korean citizens identify as independents—rising to one-third among younger voters—voter fatigue and skepticism have grown due to the repeated pattern of third-party candidates eventually merging with major parties for political bargaining.

Smaller party candidates, such as the Reform Party’s Lee Jun-seok, might consider this an opportunity to increase their minimal support (currently below 5 percent) or negotiate meaningful concessions during campaigns to increase the party’s presence in central politics.

Core Challenges Persist

Amid these new political developments, the core challenges of Korean society have intensified during the martial law crisis. The polarization between the supporters of the two major parties has only deepened, with the East Asia Institute’s 2025 attitudinal analysis on political polarization revealing alarming levels of antipathy between partisan blocs among their supporters, with disapproval ratings toward opposing parties exceeding 93 percent reciprocally. Most respondents expressed pessimism about reducing this polarization as well.

This intensification, stemming from politically constructed narratives that systematically vilify opponents and prioritize scandal-focused discourse rather than substantive policy debates, has ironically resulted in improved approval ratings for both major parties compared to the pre-martial law period. Such trends have effectively diminished the incentives to abandon confrontational political strategies that have proven electorally effective. At the same time, these metrics fail to capture the growing disenchantment among independent voters, many of whom have withdrawn from political engagement altogether.

The Path to Reconciliation

The coming months will witness an interplay between stability derived from increased political predictability and heightened confrontation inherent to electoral competition. Irrespective of presidential succession, however, it remains crucial that political leaders and civil society recognize the deeply rooted challenges of polarization and societal antagonism and collaboratively envision a reconceptualized “Korea” capable of rebuilding public confidence in democratic governance and institutions.

The impeachment verdict offers an opportunity for national reflection rather than merely closing a chapter in Korean political history. The nation must seize this chance to ensure such a crisis is never repeated. Here, the political parties and policymakers must rise above their mutual animosity to create meaningful governance visions that can guide Korea toward its future direction.

The Korean society, from political leadership to the ordinary citizens, must strive to embrace and cultivate the art of compromise and reconciliation as central democratic values, thereby putting an end to the self-perpetuating cycle of political retaliation and governance paralysis threatening institutional legitimacy, dynamics that contributed to both the martial law declaration and subsequent crisis.