A proposal to rewrite the Constitution has gained renewed momentum, with 151 lawmakers having so far joined an advocacy group in the 300-seat National Assembly. The group is now capable of setting an amendment process in motion, given that either a majority of the total members of the legislature or the president is permitted to propose a constitutional amendment.

The group says it will produce a single draft amendment for deliberation in the National Assembly by April. But its promise is a setback for President Park Geun-hye, who is opposed to a constitutional debate at the National Assembly.

In her New Year news conference last month, she compared the amendment process to a “black hole,” claiming all issues of critical national importance would be wiped away once it was formally launched. Her remark was a retreat from her previous commitments.

In 2008, she said that the earlier a constitutional debate started, the better it would be, adding that this was confirmed to be the electorate’s desire during the presidential campaign the previous year. As the presidential nominee in November 2012, she came up with a more specific proposal for an amendment, which would permit the president to serve a four-year term in office and seek reelection.

Her about-face is understandable, though. She is apparently concerned that her agenda of, among other things, raising growth potential and expanding employment will lose much of its momentum once the National Assembly starts a formal debate on constitutional revision.

Yet, the proposed debate is anything but an either-or question. Instead, she may well let the process proceed while pushing ahead with her own agenda. In other words, she does not have to keep lawmakers loyal to her from participating in the debate, as she is doing now.

The rationale behind the proposal to amend the Constitution, last revised in 1987, has outlived its goal of putting an end to the lingering specter of military-backed dictatorships. Few would now believe that the nation, which has grown into a mature democracy, is still vulnerable to military coups.

As Park is already well aware, the current constitutional system of governance, characterized by the single, five-year, presidential term in office, is an obstacle to the pursuit of long-term policy goals. This drawback is evidenced by her three-year plan for economic innovation, which is now on the drawing board. She cannot have a longer-term economic plan even if she desires one, because she has three years at most in which to enforce her policies effectively.

A president, elected for a five-year term, tends to spend the first year crafting election promises into policies before lapsing into lame-duck status in the final year. Hence, in November 2012 Park proposed adopting a four-year presidency with the option of pursuing a reelection.

Of course, the presidential system of governance is not the only power structure favored by those advocating constitutional revision. Some suggest a Cabinet system, with the prime minister being the first among equals, as an alternative to what is called the imperial presidency.

Nor should a constitutional debate be limited to a change in the governance system. Among other issues that need to be addressed are the scope of basic rights for individuals, the concentration of power in the central government and the pursuit of reunification with North Korea.

The National Assembly will do well to start an amendment process soon with a view to selecting Park’s successor, be he or she a president or a prime minister, in 2017 under a revised constitution.