The Trial of Yoon Suk Yeol: why has South Korea’s president been impeached?

South Korea’s president, Yoon Suk-Yeol, was removed from office last week after his decision to declare martial law was seen to be politically motivated and unconstitutional. For a country which has seen itself slide away from its democratic ideals under Yoon’s leadership, the snap election the impeachment has triggered might offer it a chance to heal its wounds.

Image: Daniel Bernard

Last week, a South Korean court upheld the decision to impeach President Yoon Suk Yeol, removing him from office and triggering a snap election. 

It follows months of political turmoil which began when Yoon declared martial law in December, plunging the country into a constitutional crisis and threatening the fabric of the democracy it cherishes so dearly. 

But what was behind Yoon’s decision, why was he ousted for it, and who might replace him as president?

The Power of the President

Similar to the system in the USA, South Korean political power is split between the executive branch of government (the president) and the legislature (the National Assembly, or Congress in the American example). 

The National Assembly - called the Kuk Hoe in Korean - is comprised of 300 elected members representing a number of political parties. It is responsible for drafting, debating and passing laws.

The president is elected through a separate process as the head of state and can propose legislation and executive orders, but these will still be scrutinised by the Kuk Hoe, meaning MPs (uiwon) can vote them down. 

This goes both ways, however: when a bill passed by the Kuk Hoe lands on the president’s desk, he or she has the power to veto it. It will then return to the Kuk Hoe, and will need 200 supporters (a two-thirds majority) to overrule the president and pass into law. These measures are in place to prevent any part of the government becoming too powerful.

This whole process is easy if the president and the majority of uiwon in the Kuk Hoe are from the same party. Bills proposed by the party will easily pass through the Assembly and the president will be unlikely to veto them, while his or her own proposals will gain assent from allied uiwon. 

But presidential and parliamentary elections do not align. Presidents are elected for five-year terms, while uiwon only serve four years. That means power might shift during the presidential spell in office and limit their abilities - again, similar to midterms in America. 

Yoon Suk Yeol

Yoon Suk Yeol was elected in 2022 as a political outsider ready to reform South Korean politics. His rivals - the Democratic Party (DPK) - controlled the Kuk Hoe, and his selection was considered to be in part motivated by pushback against the scandals plaguing this party. 

The aim was therefore for Yoon’s right-wing People Power party (PPP) to gain momentum during his time in office and win a majority in the 2024 legislative election, granting them the political capital to enact their agenda.

But it wasn’t to be. Yoon’s popularity tanked in the years following his election, and the man who vowed to rid the country of corruption became mired in his own string of scandals. 

The president abusing his right to veto became the common headline during his tenure. First, he blocked a bill seeking to investigate the deaths of three soldiers, leading to allegations of a cover up on behalf of senior military officials. Later, he dismissed an inquiry into claims his wife had manipulated stock prices and interfered in the PPP’s candidate nomination process. 

159 people were also killed in a crush on Halloween in capital city Seoul within months of Yoon taking the job. An inquest laid blame at the government’s door for failing to adequately prepare for the expected crowds. Yoon apologised and accepted a degree of responsibility for the disaster, but later retracted his comments, to the immeasurable anger of the victims’ families and the wider population.

The Swedish V-Dem institute, which looks at the democratic freedoms of various states, labelled the president as “South Korea’s Donald Trump” as it downgraded the country’s ranking and considered it to be transitioning to autocracy. 

For a nation proud of its juxtaposition to its pariah neighbour, these were watershed moments. All of them came back to haunt Yoon during the 2024 parliamentary election, largely seen as a mid-term evaluation of his presidency.  

The gridlock

The PPP failed to return its desired majority, taking just 108 seats. Despite actually seeing a small bump in support - attributed to their growing conservative base - the size of the defeat still proclaimed a clear mandate against Yoon’s administration. 

The opposition DPK returned 173 seats, remaining as the largest and most powerful party in the Kuk Hoe and pitching the executive and legislative branches of government against one another. 

Yoon could still veto any bills brought forward by the opposition, and since they lacked the 200 members required to force anything through without his permission he was not without power.

But the veto would not allow him to enact his own policies as the PPP lacked the uiwon necessary to support his agenda. His powers were relegated to simply frustrating the legislative process and gridlocking all government business, causing a political stalemate that could only ever anger the people he was meant to serve. 

And so Yoon became known as ‘lame duck’: with his powers strangled and his rivals largely in control of the Kuk Hoe, his approval ratings dipped to all-time lows. 

But Yoon still had one card up his sleeve, and in the chill of winter, he played it. 

The roll of the dice

One of the actions Yoon remained able to do was declare a state of emergency. This is meant to be reserved for times of extreme crisis in which decisions need to be made rapidly, transferring power away from the Kuk Hoe and into presidential hands. 

In December, he triggered this option by declaring martial law. 

His justification was that the DPK was under the influence of North Korean state actors and “communist forces”, threatening the democratic order of the country. 

Immediately, the move was denounced as a power grab by political opponents and swathes of the population. With approval ratings in freefall and his lame duck status eroding his capacity, Yoon was seen to resort to the drastic measure in an effort to regain control over state governance - and fabricate conspiracy theories to legitimise the action. 

Braving the plummeting temperatures, thousands took to the streets to protest the manoeuvre and demand Yoon’s removal from office, while the Kuk Hoe voted unanimously to compel the president to revoke martial law. 

Begrudgingly, Yoon lifted the order, but the damage had been done. With faith in his presidency completely eradicated, 204 uiwon - including 12 from within his own party - voted to impeach him.

Impeachment means there is a general consensus the president was guilty of misconduct while in power and was therefore unfit for the office. While it results in suspension, a Kuk Hoe vote cannot be used to strip away the presidency - this is to prevent it being used as a political tool by opposition parties if they have the numbers to carry the motion. 

Instead, the decision must be made by the Constitutional Court, which examines if the president indeed acted in an illegal way. On April 4, this court upheld the impeachment, determining Yoon’s actions were unconstitutional and removing him from office. 

Notably, this means Yoon has lost his immunity from criminal charges. Next week, a separate trial will begin, in which Yoon is charged with insurrection and abuse of power. A guilty verdict here could lead to life imprisonment or even the death penalty. 

The election

Yoon’s deposition has triggered a snap election schedule for 3 June - an event which has already split the population. 

Despite Yoon’s unpopularity, he retained a conservative core of voters, some of whom had protested his detention and were seen crying as his impeachment was solidified. 

Policies to overhaul the pension system, weaken trade unions and expand “silver towns” - residential complexes for the elderly - won favour with South Korea’s ageing demographic, who constitute 40% of the population. If the PPP finds the right candidate, this voter base could be a way back in from the cold. 

Han Dong-hoon, former Minister of Justice who publicly denounced his boss’ martial law order, is considered a strong contender. His moderate conservatism could pull voters who believe in the party’s positions, if not in its ex-leadership, back to their cause. 

Ahn Cheol-soo, a businessman who founded an antivirus firm, is expected to launch his own bid to be the PPP’s candidate today, while other contenders could come in the form of Oh Se-hoon, the Mayor of Seoul, Hong Joon-pyo, the Mayor of Daegu, and Kim Moon-soo, the Minister for Employment and Labour.

But even if the PPP could gain momentum, it wouldn’t change the fact their nominee would be entering their own lame duck presidency. The DPK still controls the Kuk Hoe, and the recent political turmoil has left many voters craving governmental stability more than anything. 

It’s no surprise then that the DPK are miles ahead in opinion polls. Support is rallying behind their likely candidate, party leader Lee Jae-myung, who narrowly lost to Yoon at the previous presidential election by just 0.8%. 

He believes left-wing strategy offers the economic growth South Korea is yearning for and wishes to address the country’s deep inequalities. It’s an attractive proposition to a portion of society, but the simple appeal of him being one of Yoon’s biggest critics might pay Lee the most dividends at the ballot box. 

June’s election could grant the DPK a strong mandate in both the Kuk Hoe and the presidential office, breaking the legislative deadlock which has crippled South Korean politics for too many years.

Of course, this would be a great success for the party and the people who want to see action from their leaders, not lame ducks, martial law or court cases. 

But the true winner of June’s election will be democracy. The speed with which Yoon was removed, the courage of PPP members to vote in favour of ousting their leader and the street protests of the everyday voter are all testament to South Korea’s resilience to any threat against its freedoms. 

For a country keen to differentiate itself from its autocratic neighbour, this could be a defining hour in its history.