The main opposition party, which framed the July 30 parliamentary by-elections as a referendum on President Park Geun-hye’s performance, faced a humiliating defeat, winning only four of the 15 seats at stake. Moreover, it yielded a constituency in South Jeolla Province to the ruling party for the first time since 1988.

Did the New Politics Alliance for Democracy make a grave mistake when the main opposition party set its sights on the president? Definitely not, given the evidence that her popularity had been rapidly falling. According to a survey conducted by Gallup Korea from July 29-31, her approval rating remained at 40 percent, the lowest since her inauguration.

Respondents to the poll had a litany of complaints about her performance, ranging from appointing unqualified figures to public office to mishandling the Sewol ferry disaster and failing to connect with the people. Despite the president’s low popularity, the ruling Saenuri Party staged a landslide victory.

What went wrong? Hindsight shows that zeroing in on the president’s failings was not enough for a factional strife-ridden opposition party to humble the ruling party. The electorate turned its back on the opposition when it failed to organize and develop viable policy alternatives before launching an all-out offensive against the president and her party.

Now the opposition needs to start the long process of rebuilding itself into a respectable party competent enough to replace the ruling party.

One of the first things it needs do is establish new leadership. The posts must be filled as soon as possible now that cochairmen Kim Han-gil and Ahn Cheol-soo have resigned, taking responsibility for the defeat.

In changing the guard, the opposition will have to keep factional strife from rearing its ugly head again. Instead, each faction should be encouraged to engage in fair and orderly competition in their attempt to take control of the party. If memory fails to serve, all factions should be reminded that their cutthroat competition for nominations ahead of the by-elections was one cause of the electoral defeat.

With the next general elections in April 2016, the opposition under new leadership will have ample time to refurbish its public image. It needs to endear itself not only to its traditional progressive supporters but also to more swing voters if it wishes to win.

The opposition cannot foray into the center and the center-right unless it sheds its ideological rigidity, crafts more inclusive policy proposals and recruits new blood, including those with practical ideas. It will be of no help, for instance, to attempt to ostracize a politician for supporting free trade agreements.

The opposition’s rightward shift will be critical in its future electoral strategy, and all the more so, given that the Park administration and its party are already co-opting some of the opposition’s progressive policy proposals. They include a fairer income distribution, as evidenced by their demand that large corporations pay out more in wages as well as dividends, instead of keeping an excessively high level of retained earnings.