South Korea’s main opposition Democratic Party (DP) has regained momentum after losing ground in January, recent polling data suggests, as growing concerns over the economy, strategic messaging and impeachment proceedings drive changes in public opinion at a sensitive political moment for the country.

But the Seoul Central District Court ruled on Friday that President Yoon Suk-yeol’s arrest was procedurally flawed, potentially leading to his release from custody, and the development could alter public sentiment ahead of the Constitutional Court’s expected impeachment ruling next week.

Though the ruling does not assess the severity of Yoon’s Dec. 3 martial law declaration, it will likely embolden his supporters and shape political dynamics in the days ahead.

With the Constitutional Court set to issue a verdict that could either remove or reinstate Yoon, the coming weeks are likely to be politically volatile, but strong centrist voter support for impeachment suggests that the opposition has the upper hand.

DEMOCRATIC PARTY REGAINS LEAD

In early March, the DP overtook the ruling People Power Party (PPP) in National Barometer Survey (NBS) polling for the first time since January, when Yoon’s arrest on Jan. 15 temporarily united conservative voters.

According to the latest data, the DP stands at 35% compared to the PPP’s 34%, within the margin of error. Gallup Korea’s polling shows a more decisive lead, with DP support at 40% and PPP at 36%.

A key factor in this shift may have been DP leader Lee Jae-myung’s Feb. 18 declaration that his party represents “centrist conservative” values rather than traditional progressivism. This strategic repositioning appears to have resonated with moderate voters, particularly as the country’s economic and security uncertainty grows.

The PPP’s support, which had remained steady at around 37% in February, has since declined by three percentage points. Meanwhile, the proportion of undecided voters has risen from 17% to 20%, suggesting increased political uncertainty amid the impeachment proceedings and the possibility of an early presidential election.

Main opposition Democratic Party leader Lee Jae-myung | Image: Democratic Party of Korea, edited by Korea Pro

ECONOMIC CONCERNS INFLUENCE POLLING

Economic conditions may have played a crucial role in voter sentiment.

The Bank of Korea’s recent interest rate cut and downward revision of GDP growth forecasts have heightened concerns about financial stability. 

The timing of these developments, coinciding with Yoon’s final martial law defense statement and U.S. President Donald Trump’s hardening trade policy, likely contributed to growing discontent among voters who prioritize economic stability.

Further complicating matters for the ruling party, revelations from leaked conversations between Myung Tae-gyun, a self-described political broker, and the first lady on Feb. 24 have fueled allegations of corruption. While the full impact of these disclosures remains unclear, they have added to a growing number of centrist voters’ distrust in the Yoon administration and the PPP.

IMPEACHMENT SUPPORT REMAINS STEADY — FOR NOW

Despite conservative protests and Yoon’s legal team denouncing the impeachment process as fraudulent, public support for his removal has remained stable. 

NBS polling shows impeachment support at 56% in early March, up slightly from 55% in mid-February after weeks of gradual decline. Meanwhile, Gallup Korea has consistently measured impeachment support at around 60%.

Notably, support for Yoon’s removal from office among centrist voters is at over 70%. This demographic has also shown a consistent preference for a transition of power in the next presidential election, with 61% to 62% favoring a DP-led government, more than double the support for continued conservative rule.

Public confidence in the Constitutional Court’s handling of the impeachment process has also stabilized. NBS polling shows trust in the court rebounding from a dip in late February, when it fell from 55% to 52%, before recovering to 54% in early March.

The large-scale protests among pro- and anti-Yoon protesters that erupted across major cities on March 1 appear to have had a minimal impact on centrist voters. This suggests both camps have likely reached their peak influence, with little room for further impact.

Yoon Suk-yeol addressing the nation about his Dec. 3, 2024 emergency Martial Law | Image: ROK Presidential Office (Dec. 7, 2024), illustrated and edited by Korea Pro

PRESIDENTIAL RACE TAKES SHAPE

Beyond immediate political maneuvering, the latest presidential preference polls indicate that Lee Jae-myung continues to lead his conservative rivals by a comfortable margin. NBS data shows Lee leading with 29% support, while the highest-polling conservative candidate, Labor Minister Kim Moon-soo, stands at just 10%.

Other potential PPP candidates, including Seoul Mayor Oh Se-hoon, Daegu Mayor Hong Jun-pyo and former PPP leader Han Dong-hoon, lag behind with single-digit support. Gallup Korea’s polling paints a similar picture, suggesting potential fragmentation within the conservative camp.

PUBLIC PRIORITIES AND POLICY VIEWS

Issue-based polling highlights key voter priorities. While centrist voters appear to lean toward conservative economic policies, they also demand strict political transparency and expect political leaders to adhere to ethical norms.

Business-friendly policies, such as modifications to the semiconductor sector’s 52-hour workweek exemption, receive majority support, with 56% backing the measure.

On the other hand, progressive fiscal policies appear to be unpopular among centrist voters. For instance, only 34% of the public supports the DP’s cash voucher proposals, while 55% oppose them. Similarly, inheritance tax reductions enjoy significant backing, with 52% of centrists and even 43% of self-identified progressives in favor.

Such figures may help to explain Lee Jae-myung’s decision to pivot the DP — once led by progressive stalwarts such as Kim Dae-jung and Roh Moo-hyun — toward “centrist conservatism.”

Meanwhile, support for increased political transparency is strong across the board. The Myung Tae-gyun special prosecution bill, which aims to investigate alleged political corruption, has 60% backing in NBS polling and 59% in Gallup Korea surveys, signaling a broad consensus on accountability measures.

South Korea’s eight Constitutional Court justices preside over President Yoon Suk-yeol’s fourth impeachment hearing | Image: ROK Constitutional Court (Jan. 23, 2025), edited by Korea Pro

OUTLOOK: CENTRISM AND ACCOUNTABILITY

The DP’s ability to maintain a centrist economic message while emphasizing political accountability appears to be a winning strategy. 

In contrast, the PPP faces an uphill battle in reclaiming centrist voters, especially as Yoon’s supporters escalate protests and attempt to undermine judicial integrity.

If the Constitutional Court upholds Yoon’s impeachment, the PPP will need to swiftly address its candidate fragmentation problem and develop a coherent message that extends beyond its conservative base. Failing to do so could deepen its electoral challenges and solidify the DP’s advantage heading into the next election cycle.

Edited by John Lee