President Moon Jae-in’s ruling Democratic Party of Korea won a landslide victory in local elections on Wednesday – almost certainly benefiting from a feel-good factor that follows fast-moving developments in regard to inter-Korean rapprochement and peace on the peninsula.

South Koreans went to the polls one day after the historic Singapore summit between North Korean leader Kim Jong-un and US President Donald Trump, a meeting which Moon did much to broker.

The elections, for governors and mayors nationwide, were the first public plebiscite on the administration of Moon, who took power in a snap election in May 2017, following the ouster of disgraced conservative President Park Geun-hye after a corruption and influence-peddling scandal that prompted Koreans to take to the streets in their millions.

Moon and his party now have a two-year window of opportunity before the next significant political challenge: National Assembly elections in 2020.

The outcome, which had been widely predicted, confirms that the conservative opposition is in utter disarray. The Liberty Korea Party has been flailing since the ouster of Park. The former president is serving a 24-year jail term, while her predecessor Lee Myung-bak – like Park, a conservative – is currently detained and on trial for corruption.

The victory saw the liberal DPK grab 14 out of the country’s 17 major provincial governorships and mayoral seats – doubling their numbers prior to the election. In further good news for the liberal camp, the DPK won 11 out of 12 vacant National Assembly seats up for grabs in by-elections, also held on Wednesday.

In the capital, sitting mayor and Moon ally Park Won-soon rousted the opposition, capturing just under 53% of votes and becoming the first three-term Seoul mayor ever. The right-wing LPK’s Kim Moon-su came in second, while the centrist Bareunmirae party head Ahn Cheol-soo came third.

The Seoul mayorship is widely seen as an avenue to the presidential Blue House, suggesting that Park, a former social activist, is well placed if he makes a bid in the next presidential race in 2022. The incumbent, Moon, is limited – like all Korean presidents since democratization in 1987 – to a single, five-year term.

Ahn, a former entrepreneur and academic widely lauded for his clean, fresh take on politics, was once the great hope for middle-of-the-road politics in Korea. His loss is yet another disappointment after two failed presidential bids and must raise questions over his political future.

A leadership shuffle is widely anticipated in the LKP.

“The party is grateful for such great support to boost our efforts in pioneering the way for peace,” DPK chairwoman Choo Mi-ae said in a televised interview. “The party views the voters have lauded the ruling camp’s bid to put an end to the Cold War and pave the way toward peace and prosperity.”

While local elections have little impact on national and international policy-making, they provide a morale boost for Moon and his party as they push their agenda. Flagship policies include engaging North Korea, removing wartime operational control of Korean troops from US hands, and raising the minimum wage.

However, in three policy areas, the president and DPK have been disappointed.

Attempts at constitutional reform and a pivot away from nuclear power generation have foundered. Above all, Moon’s widely anticipated drive to reign in the powerful chaebol – the family-run conglomerates that dominate the national economy and wield significant influence in wider society – has thus far proven weak-kneed, though new legislation and regulations are expected nearer to the end of the year.