Now that the parliamentary election is over, political parties are shifting their focus to the presidential race. The Wednesday election was widely viewed as the precursor to the December poll. Yet there is no guarantee that the Saenuri Party victory will be repeated in eight months’ time.

To win the crucial election in December, political parties should listen to the vox populi expressed in the parliamentary poll. This applies to the ruling Saenuri Party, as well as to the main opposition Democratic United Party, which underperformed expectations.

The Saenuri Party scored a dramatic victory on Wednesday. In light of the heavy pre-election odds against it, the party’s performance can be seen as a shining success. By garnering 152 of the 300 seats, it managed to retain its absolute majority.

Yet that majority has sharply dwindled ― the party lost more than a dozen seats while the DUP boosted its share from 81 to 127 seats. The margin is even slimmer when the 13 seats gained by the DUP’s election partner, the United Progressive Party, are taken into account.

The electorate’s message is unmistakable. By giving the ruling party a parliamentary majority, they have chosen to keep it in the driver’s seat. But by slashing its majority, they made strident calls for change. The message thus can be summed up as “reform amid stability.”

Hence, for Park Geun-hye, the ruling party’s presidential aspirant who burnished her reputation ― the “queen of elections” ― by almost single-handedly pulling off the upset victory, there is little room for complacency. She needs to push for bold reforms to address voter discontent with the present government.

In a press conference on Thursday, Park pledged to bring in new legislation to prevent the illegal surveillance of civilians by government officials. This is a move intended to placate public outcry over the unwarranted spying on civilians by officials of the Prime Minister’s Office and the alleged cover-up attempt by the presidential office.

Park needs to promote reform in other areas. For instance, she should push for reform of the prosecution, which has lost public trust by failing to maintain political neutrality in several high-profile investigations.

Yet in pursuing her reform agenda, the Saenuri leader is likely to be severely constrained by the new balance of power in parliament. Given its beefed-up presence, the opposition camp is unlikely to recognize the ruling party’s leadership in handling state affairs and steering the National Assembly.

Furthermore, smarting from the Wednesday defeat, the two opposition parties are set to step up attacks against President Lee Myung-bak and the Saenuri leader in a bid to shape the presidential race in their favor.

In this new political environment, Park faces a harsh leadership test ― she is required to walk a fine line between confronting a hostile opposition and enlisting its cooperation to press ahead with her reform initiatives. If she fails this test, there would a political deadlock and parliamentary paralysis.

For the DUP, the Wednesday election provided an embarrassing reality check. The party has rightly tapped into anti-incumbent sentiment among voters. Yet, overconfident of its victory, it had made several painful mistakes in the nomination process, which it did not bother to correct.

The party also lost public confidence by foolishly trying to negate policies that it had initiated itself while in power, such as the Korea-U.S. Free Trade Agreement and the construction of a naval base on Jeju Island.

The cost of its hubris was a blown opportunity to grasp parliamentary control. Yet, just as the Saenuri Party managed to come from behind in the parliamentary poll, the DUP can do it in the more important presidential vote ― if it avoids repeating the same errors.

The party’s potential was demonstrated by the dominance of the DUP-UPP alliance in the capital zone, a region of vital importance in the presidential poll. Furthermore, the alliance received more votes than the Saenuri Party in the contest for proportional representation seats, an indication that its support base is broader.

To win the presidential race, the DUP should know better than to oppose government policies for boneheaded reasons. Doing so undermines not only its trustworthiness but national interests. More importantly, the party needs to find a presidential candidate who can compete with Park. It may have to court Ahn Cheol-soo, the popular IT businessman-turned-professor.