Voter anger over Yoon Suk Yeol's martial law propels Lee Jae-myung to victory

Lee Jae-myung, presidential candidate of the liberal Democratic Party of Korea, raises his arms during a final campaign rally in Yeouido, Seoul, Monday. Joint Press Corps

Liberal Democratic Party of Korea (DPK) candidate Lee Jae-myung's victory in Tuesday's snap presidential election reflects widespread public anger over former President Yoon Suk Yeol's abrupt martial law declaration and a strong desire for a change in power.

Voters, outraged by Yoon's attempt to impose emergency military rule on Dec. 3, 2024 — the move that led to his impeachment and the early election — delivered a stinging rebuke to the main conservative party, with many turning away from People Power Party (PPP) candidate Kim Moon-soo, analysts said.

Lee's victory marks a political resolution six months after the country was plunged into turmoil by Yoon’s surprise declaration of martial law, which lasted for just six hours. Yoon claimed the move was necessary to counter what he described as "anti-state forces," but it instead sparked mass protests that ultimately led to his impeachment in April.

The election was widely viewed as a referendum on Yoon’s leadership, unfolding under the ominous specter of martial law. As the campaign progressed, the impeached president faced a criminal trial on charges of insurrection.

"Every election has a central issue that drives public opinion. In this case, it was about holding those behind the martial law attempt accountable," said Eom Kyeong-young, director of the Zeitgeist Institute, a political think tank.

Eom noted that Lee’s victory was driven less by his leadership credentials and more by a public desire to break with the lingering influence of those associated with martial law.

"The DPK effectively framed the race around the need to end the so-called insurrectionist forces and put guardrails on presidential powers concerning martial law. In contrast, the PPP’s Kim failed to offer a clear message on how to address the aftermath of the martial law crisis," he said.

Lee’s campaign message — promising constitutional reforms and a restoration of democratic norms — appeared to resonate with voters still unsettled by Yoon’s authoritarian shift.

Lee Jun-han, a political science professor at Incheon National University, said Lee benefited from being viewed as a more prepared leader than his rival, whose candidacy was marred by a chaotic PPP primary. The party’s leadership had attempted to unilaterally replace its primary-elected candidate, Kim, with former Prime Minister Han Duck-soo — a move it later reversed following intense backlash from party members.

"The DPK did a good job shaping the perception that Lee was the only viable option among liberal voters. A month ago, his approval rating was actually lower than his own party’s. But after he was officially nominated, his numbers surged. That reflects the sense that there was no alternative," the professor said.

Supporters cheer during Democratic Party of Korea presidential candidate Lee Jae-myung's rally in Yeouido, Seoul, Monday. Yonhap

Kim, who served as labor minister under the former Yoon administration, struggled to overcome his close ties to the disgraced president — a liability that proved politically damaging.

"Yoon’s tarnished legacy did little to help the PPP during the campaign,” the professor said. "Kim appeared to lack an effective strategy to appeal to swing voters frustrated with the Yoon administration."

The series of missteps among conservatives created an opening for the liberal candidate, who was also grappling with his own weaknesses.

Lee is currently on trial for multiple criminal charges, including alleged election law violations — a central line of attack for his opponents. His firm control over the DPK has also drawn criticism, with some accusing him of suppressing internal dissent.

However, during the campaign, the liberal politician successfully portrayed himself as a victim of political retaliation and a symbol of democratic resistance.

Lee's anticipated election victory marks the DPK's return to power in just three years. It echoes the liberal party's resurgence in the 2017 snap election following the collapse of the conservative Park Geun-hye administration amid a corruption scandal.