SEOUL (WASHINGTON POST) - To South Korean conservatives, United States President Donald Trump looked like an ally.

His tough talk on North Korea, his pro-military views and his disdain for liberal politics - all of it fit neatly with the ideas that had ruled the right here for decades.

But almost 18 months into his presidency, many acknowledge that Trump has been a disaster for South Korea's beleaguered conservative movement.

"I still can't wrap my head around it," Hong Joon-pyo, former leader of the country's largest right-wing party, Liberty Korea, said of Trump's meeting with North Korean leader Kim Jong Un in Singapore on June 12. "I never imagined a US government would help a leftist government in South Korea."

In a nation where the political right has long based its policies on deep animosity toward North Korea and unfailing support for the US military alliance, conservatives now find themselves dealing with an American leader who is not only willing to meet with and praise Kim, but who publicly muses about withdrawing troops.

South Korea's rightists are in the midst of a full-blown identity crisis. And the effect can be seen in electoral votes and opinion polls.

In regional elections on June 13, the Liberty Korea Party suffered a humiliating defeat, garnering just two of 17 major mayoral and gubernatorial seats and only a little more than half the votes that the governing Minjoo Party received.

Liberal candidate Moon Jae-in beat Hong in last year's presidential election by more than 17 percentage points. As president, Moon now enjoys sky-high approval ratings of around 70 per cent, suggesting that many former supporters of conservative parties are backing him.

With parliamentary elections due in 2020, Liberty Korea is in the process of reimagining South Korean conservatism in a desperate bid to retain political relevance.

For Kang Yean-jae, a losing candidate for the party in June's regional elections, the outlook for the right is as bad as it gets. "It's not going to survive unless it changes completely," Kang said.

Among older right-wingers like Hong, the despair is palpable. During a recent meeting at a Japanese restaurant in Seoul's upmarket Jamsil neighbourhood, Hong wore a red blazer and shirt - a nod to the colour of South Korean conservatism.

But although his brash tone had once earned him comparisons to Trump, Hong now distances himself. "Trump turned out to be a person who takes diplomacy as something similar to a business transaction," he said. "He didn't stick to his words."

The rot in South Korea's conservative movement set in before Trump's detente with North Korea. It accelerated with a string of scandals surrounding conservative former president Park Geun-hye that left the movement deeply divided.

The daughter of former president Park Chung-hee, an autocrat who presided over an economic boom only to be assassinated in 1979, the younger Park made history as South Korea's first female president in 2013. But allegations of cronyism soon saw her domestic support drop off dramatically.

By November 2016, her approval rating was just 4 per cent, the lowest ever recorded in South Korea. In a subsequent impeachment vote, almost half the lawmakers from her own party voted against her. Park was removed from office last year and in April was sentenced to 24 years in prison.

The impeachment caused a schism among conservatives. Some were aghast at what their leader had done and distanced themselves from her Saenuri Party, later rebranded as Liberty Korea.

"I can understand someone going left or going right - that's a choice they made - but she was going down to the basement," said Lee Jun-seok, a Harvard-educated conservative who left Saenuri over the scandal.

Yet support for Park persists, most fervently in the Korean Patriots' Party, which holds frequent rallies to protest her imprisonment. This group had once seen Trump as its saviour; supporters waved American and Israeli flags and called on him to not only help release Park but pre-emptively strike North Korea, too.

Since the Singapore summit, Trump's face has been strikingly absent from pro-Park rallies. Seo Seok-gu, an attorney for Park who spoke at a rally in June, said many were disappointed that Trump had met with Kim a day before local elections here.

"We conservatives were criticising the dictator Kim Jong Un," Seo said. "Why did Mr. Trump praise the North Korean dictator so openly?"

The divide limits the movement's collective power. The Korean Patriots' Party has just one member in the 300-seat parliament, but Bareunmirae, a smaller, center-right party that includes conservatives who distanced themselves from Park, has 30 seats. Liberty Korea is by far the largest with 112, but it remains split along pro- and anti-Park lines.

To win more seats in 2020, conservatives will have to think of a way to reach out to young voters, who polls show largely support Moon and the North Korean talks he has pushed.

Recent reports that South Korea's military had drawn up plans for martial law during the mostly youth-led anti-Park protests have made that harder."That's actually the problem for the conservative parties now," said Kang Won-taek, a political-science professor at Seoul National University. "There's no fresh look." An emergency committee will decide the new leadership of Liberty Korea - and with it, a new face for South Korean conservatism. But with the party's historic platforms now appearing out of touch with the Korean public and U.S. leadership, the path is unclear.

Some conservatives say they should stick to their guns, that North Korean talks will soon break down and that their supporters could come back.

Moon Chung-in, a liberal academic and adviser to the president, agreed that conservatives' fortunes could rebound if North Korean talks fail.

"In South Korea, conservatism is not dead - it's well and alive," he said, noting the power of major conservative newspapers such as Chosun Ilbo.

Others, though, argue that Liberty Korea needs to pivot as the country changes. Kang Yean-jae, who joined the party this year, said it's clear that people want peace with North Korea. Conservatives need to accept that, she said, while serving as the voice of caution.

Lee, who at 33 sees himself as one of a young generation of conservatives who want to put more focus on economic matters, said a bigger change was possible, too: Conservatives may finally be rethinking their absolute reliance on the US military.

"It was inevitable," Lee said of the shift. "It's just changing earlier than we thought.""Actually, I'm looking forward to it," he added.

For older conservatives like Hong, such an adaptation could prove harder.

Taking a break from politics, Hong flew to Los Angeles on Wednesday. He said his plan is to stay in the United States for the next few months - studying North Korean issues.