The two main contenders for Wednesday’s presidential election have both suggested reforming politics as one of their signature campaign pledges. Conservative candidate Park Geun-hye and her liberal rival, Rep. Moon Jae-in, agreed to make joint efforts to pass political reform bills through parliament during their first TV debate on Dec. 4.

But they should now feel ashamed that their campaigns have become preoccupied with actions that make their calls for political change sound hollow. It might not have been their intent, but voters now see an increasingly nasty exchange of smears between their camps, which charge each other with making false accusations and slander.

With polling day approaching, their supporters may be more tempted to try to taint the image of the opposing candidate. They may think such methods could be more effective in winning the race, as the two main candidates have similar pledges on matters related to the people’s livelihoods.

We believe Park of the ruling Saenuri Party and Moon of the Democratic United Party are wise enough to know that will not be the case. Voters have become less susceptible to negative campaigns after having seen many controversial allegations raised in previous elections turn out to be false. Moreover, the two contenders for the next five-year presidency appear relatively clean and free of any damaging scandals. That means they are not as vulnerable to smear campaigns as some presidential challengers and attempts to defame them would be of little help in boosting their chances.

Their campaigns have been described by critics as lacking messages that inspire the public, long-term visions for the nation and vitality to pique voters’ interests. The election is overshadowed by the legacies of two late presidents ― Park Chung-hee, the father of the Saenuri candidate, and Roh Moo-hyun, for whom Moon worked as chief secretary.

But what is remarkable in this poll is the absence of extreme animosity between the two main candidates. With both of them having a relatively rational and moderate personality, they propose similar approaches to a range of issues from reforming politics to reducing economic inequality and handling the unpredictable regime in Pyongyang.

In the final stretch of the presidential race, they must ensure that their electioneering will not be further tarnished with negative means. They should prove their will for political reform by practicing a clean and fair campaign.

It is regretful to see their initial pledges to refrain from negative campaigns betrayed by a flood of accusations on the Internet.

Park had to go extra lengths to rebuff allegations that she was linked to a dubious religious group and paid 150 million won ($140,000) to a shaman for a ritual to help disperse criticism surrounding a scholarship foundation she had once led. A DUP lawmaker apologized for claiming on his Twitter account that Park tried to cheat during a nationally broadcast debate on Dec. 10 by carrying a tablet PC with her.

Moon was also subject to false accusations that he had a luxurious house similar to that owned by the head of the country’s largest conglomerate and that his father, who actually fled to the South during the 1950-53 Korean War, served as a North Korean military officer.

The two candidates’ camps clashed last week over an allegation by DUP officials that an apartment in southern Seoul was being used by an agent of the National Intelligence Service to post negative comments about Moon online. Park came forward Friday to declare an “all-out war on false propaganda,” while Moon said later in the day the Saenuri candidate overreacted to divert public attention from suspicions of her campaign team being involved in a separate illicit electioneering scandal.

During rallies over the weekend, the two contenders vowed efforts to prevent smear campaigns from further escalating, saying it would harm national unity. Their pledges should be followed by concrete actions. Election officials are urged to take tougher measures against the spread of slander and false accusations.

Stopping the presidential race from being severely tainted by negative electioneering is also needed to ensure bipartisan cooperation after the election in dealing with crucial tasks the next administration will face. Voters here were impressed with U.S. President Barack Obama and his rival contender Mitt Romney having a private lunch at the White House after Obama’s re-election last month. It is hoped that Park and Moon would have a similar meeting after Wednesday’s vote, setting a valuable precedent in the country’s bruising politics.