Illustration: Liu Rui/GT

In South Korea's presidential-dominated system, it is almost impossible for a prime minister, who is appointed by the president, to be powerful and effective.

Those who had actual power did so because they were given more power and leeway by a president who believed in separation of powers.

Most of the time, South Korea's prime ministers, the second highest official, function as "bulletproof glass" or "wind shields" for the president.

They deal with the parliament on behalf of the president and take responsibility for major political events, which usually results in resignation at the end. Since 1948, more than 60 prime ministers served about one year on average.

For instance, former prime minister Chung Hong-won, offered to resign shortly after the tragic Sewol ferry incident in April 2014, even though it was President Park Geun-hye who in tears said she took the full responsibility in a televised speech.

The most recent prime minister to resign is Lee Wan-koo, who was supposed to be the executor of Park's new anti-corruption campaign.

In mid-March, Lee declared an all-out war against corruption. "The fate of the country depends on uprooting corruption. The government will make all efforts possible and accomplish the mission at any cost," Lee said in the first statement to the nation. The war against graft came as South Koreans are frustrated with numerous bribery cases and the supply of substandard military equipment.

More importantly, it was the president's secret weapon to break through her political impasse and declining approval rates which put her on the verge of becoming a lame-duck president at the beginning of only her third year in office.

Unfortunately, only less than one month later, Park's endeavor has become a failure as the prime minister himself has been put at the center of a corruption case.

Lee's first targets included an influential businessman that participated in a "resource diplomacy" project, one of the core businesses of the previous administration of Lee Myung-bak. The tycoon, accused of bribery, killed himself and left a list of several high-profile politicians including Lee and the former and current secretaries in chief among those who received illicit funds from him, mostly close aides to the president and the ruling Saenuli Party.

Faced with prosecutorial investigations and severe criticism, Lee offered to resign on April 20 as he held the reins of the government while the president was traveling in Latin America.

Coming back from her 12-day trip, Park accepted Lee's resignation on Monday and now faces something that has proved to be a very difficult task under her administration; finding a decent prime minister.

Park has already nominated five prime minister candidates during the last two years. Three failed to pass scrutiny due to their moral lapses or controversial historical view even before they took the office while Lee and his predecessor stepped down in disgrace.

The biggest mistake the president has made this time is ignoring the simplest rule: The pot cannot call the kettle black. During the confirmation hearing, Lee had shown several moral lapses such as multiple cases of speculation in property and a dubious exemption from military service.

And the ignorance might represent that the administration underestimates social changes in South Korea. Citizens have higher standards and more wanted, or unwanted, information is available to expose politicians. But many political analysts blame Park for being so fixed on selecting government officials only from her small pool of people that the same mistakes keep being repeated.

As these scandal-inviting mistakes repeatedly show, ordinary people are the biggest victims. Dealing with disappointment over politicians and the government can be considered mere psychological distress and humiliation. But as the government is distracted with bandaging personnel matters rather than revitalizing the stagnating economy and addressing many other urgent agendas, South Korean people are watching the search for sixth prime minister nominee by Park uneasily. 

The author is a reporter with the Global Times. gayoungpark@globaltimes.com.cn