South Korea's elections driven by voters' desire for reform

When the popular independent candidate Ahn Cheol-soo pulled out of South Korea's presidential contest last month, he completely changed the odds in a race that might have marked a new phase in the country's history.

Now only two candidates are still in the running, representing the main conservative and progressive camps, which have been squabbling over power since the end of the dictatorship in the late 1980s. On the right is Park Geun-hye, 60, standing for the ruling New Frontier party, and on the centre-left Moon Jae-in of the opposition Democratic United party.

The end of the bargaining process to designate a single opposition candidate – which has so far monopolised the electorate's attention – and the official campaign's launch should prompt more lively debate before the 19 December poll.

But Ahn's bid has not been wholly wasted,coalescing public condemnation of traditional political practices and forcing both right and left to move closer to the centre on the two key sources of concern for public opinion: social justice and a shift in policy towards North Korea.

The decision to pull out of the race was prompted by memories of the 1987 election, when two opposition candidates – Kim Dae-jung and Kim Young-sam – both fought it outto the bitter end, facilitating the election of Roh Tae-woo, a retired general close to the dictatorship, which had finally yielded to popular unrest.

Having failed to reach agreement with Moon on a single candidate, Ahn decided to throw in the towel rather than hand the presidency to Park on a plate. She would have been sure of victory in a contest with a divided centre-left.

Ahn had come to symbolise rejection of politics plagued by infighting and regionalism, and out of touch with contemporary society. In less than a generation, South Korea has cast off poverty to join the ranks of Organisation for Economic Co-operation and Development countries. But Ahn was not entirely convincing as a candidate.Though refreshing, his lack of political experience was a serious drawback in his bid to become the sole representative of the centre-left.

His moderate, reformist platform – what he called "common-sense politics" – encouraged the two other candidates to set aside their ideological legacy and shift closer to the middle ground, which perhaps explains the similarities in their manifestos. They differ mainly on how far the measures they propose should go, but agree in their diagnosis of social and economic ills.

"Korea has become a republic of angry citizens," says Lee Chung-min, professor of international relations at Yonsei University and one of Park's advisers. "Students are under great pressure to pass their exams; young couples struggle to find a home; people in their 40s are scared of losing their job; and seniors feel abandoned." Demand for change is so far-reaching that "political platforms are secondary", contends Chun Gi-young, a columnist on the centre-right daily Joong Ang. "The decisive factor will be a candidate's ability to represent a break with the past." The centre-left daily Hankyoreh endorses this analysis, writing: "The winner will be the one who is seen as best equipped to embody the present mood."

The big uncertainty in this poll, which promises to be a tight contest, is which way Ahn's supporters will lean. Amounting to nearly a quarter of the electorate, their vote will be decisive. Moon is doing his utmost to take them on-board, hiring Ahn staffers for his campaign team.

Im Sang-ryeol, head of the pollster Research Plus, believes at least half of Ahn's backers will opt for Moon. But what will the rest do? Disappointed and embittered, they reject both the conservatives and the centre-left, which is still a long way from being the European-style social democrat party they want.