The Constitutional Court’s historic decision to oust Park Geun-hye as president confirmed what many of us had believed: The president has too much power and it paved the way for Park to abuse her power for the personal gains of her confidante.

As the court found, the basic element of the influence-peddling and corruption scandal involving Park and Choi Soon-sil is that Park abused her power as president to help Choi earn personal gains through foundations and companies she controlled.

Since the scandal broke last October, there have been persistent calls for -- in addition to punishing Park -- finding a fundamental solution to the problem such as through revising the Constitution to curb the power of the president.

The calls to rein in the president’s power got a special boost from one of the eight Constitutional Court justices who made a unanimous verdict to oust Park on Friday.

In a rare “supplementary opinion” to the impeachment verdict, Ahn Chang-ho opined that the root cause of the Park-Choi scandal lies with the concentration of power in the president.

The justice said that the current constitution, revised in 1987 in the wake of a pro-democracy movement, secured legitimacy for the presidential power. He referred to the reinstatement of a popular, direct vote for election of the president that ended the successive military dictatorships, which began with Park’s father, the late President Park Chung-hee, in 1961.

But, Justice Lee said, the 1987 basic law still allowed the president to exercise power in the same authoritarian way as past dictators, with lack of effective checks on the power of the president.

Lee said that “imperial presidency” fostered all the ill practices that were related with the Park-Choi scandal: interference in state affairs by the president’s civilian associates, abuse of presidential power and collusive ties between the president and businesses.

Lee did not mention this, but freeing powerful agencies such as the prosecution, tax service and antitrust and financial watchdogs from the president’s control is also essential for preventing the president from abusing power.

It is an open secret that past presidents used the powerful agencies for political purposes -- like the taming of political opponents or businesses. Business tycoons who made donations to foundations run by Choi said they could not reject demands from the president or her aides for fear of reprisals from the government.

All these problems reaffirm the need to change the current power structure to one in which the president shares power with other institutions such as the prime minister and the National Assembly.

Alternative power-sharing structures suggested by Lee included a semi-presidential or double executive system, in which the president shares power with the prime minister, and a parliamentary cabinet system.

Lee also suggested bold decentralization and the introduction or expansion of elements of direct democracy such as recalls, popular initiatives and referendums.

Many of Lee’s suggestions are nothing new. But as he said in the verdict, the court’s decision to uphold the parliamentary impeachment of Park, the first such ruling in history, should be regarded as a command to reform the power structure.

The need to revise the Constitution has become more urgent as the nation should elect a new president within 60 days of the court’s decision to oust Park.

Some leading politicians -- from both liberal and conservative groups -- have been calling for revision of the Constitution ahead of the presidential election, which is likely to be held on May 9.

But Moon Jae-in, the leading liberal candidate, and his Democratic Party of Korea are least positive toward amendment of the basic law, as they see they are within reach of power.

Moon and the Democratic Party need to heed Lee, who said the impeachment of Park was neither a matter of dispute between liberals and conservatives nor a judgement on past illegal acts. As Lee said, it should help set a new standard for the future of the republic. The first step for achieving the standard is to abandon the imperial presidency.