South Australia election 2026: One Nation surge threatens Liberal Party collapse as Peter Malinauskas leads Labor landslide

One Nation trouncing the Liberal Party in South Australia’s imminent state election could shake up politics across the country, a top political scientist says.

State polls have consistently put the far-right populist party’s core support well above the beleaguered Liberals, who have weathered high leadership turnover and failed to find sticking attack lines on the centrist Labor government.

The worst polls have suggested state opposition leader Ashton Hurn, who only took up the reins in December, could be facing a party-wide wipe-out.

Political scientist and Flinders University associate professor Rob Manwaring told NewsWire it was a realistic scenario that could have major implications for future elections as One Nation pursues federal and state seats across Australia.

“One Nation has been steadily tracking between 22 to 28 per cent on the primary votes for quite some time and I think the key thing with the polls is the trend data rather than just necessarily one-off polls,” he said.

“It would strike me that there’s a solid and sizeable minority of first preferences that would go to One Nation.”

He said he expected that to translate into one or two lower house seats and a comfortable two upper house seats.

With the Liberals holding just 13 of the 47 lower house seats and eight of the 22 upper house seats, Dr Manwaring said it posed an existential threat amid growing primary support for Labor.

“The polling probably has the Liberal Party reduced to single digits in seats and that will really diminish their base,” he said.

“I think most of the change will be Liberal seats going over to the Labor Party.

“I think we’re expecting probably the most historic Liberal loss in the party’s history here in South Australia.”

Polls have unanimously shown Premier Peter Malinauskas on track to lead Labor to a landslide, with the latest Advertiser/YouGov survey putting his party’s primary support at 38 per cent to One Nation’s 22 per cent and the Liberals’ 19 per cent.

Mr Malinauskas was also well ahead as preferred premier at 62 per cent to Ms Hurn’s 23 per cent.

Dr Manwaring said Labor’s popularity was driven by several factors but that the looming red landslide was “probably as much due to Liberal ineptitude as it is to Labor governance”.

“Firstly, you’ve got to say just how badly the Liberals have been run here in South Australia,” he said.

“We’ve had four leaders in four years, so that leadership churn is a real problem for the party.

“Secondly, they’ve had long standing factional battles, and there’s been at times almost open warfare between the conservative and moderate factions of the Liberal Party.

“And then the third element, the problem for the Liberal Party in South Australia is much of their vote is locked up in regional and rural areas.

“But to win office, you need to win the marginal, metropolitan and ultra metropolitan seats, and they just don’t have that presence.”

He also said it was reflective of a broader “existential crisis” gripping the Liberal Party nationwide.

“There is just a general and existential crisis in the Liberal Party … and this has really played out at the federal level and it’s playing out in a number of states and territories,” Dr Manwaring said, adding that he had not yet seen a “federal Liberal leader able to resolve that crisis”.

“The Liberals had nearly a decade in power but actually, that masked a lot of the problems that the Liberal brand and identity are in.”

Anthony Albanese on Thursday cautioned that voters would not find “solutions” by casting ballots for One Nation.

Instead, he urged Australians to vote for “parties of government”.

“One Nation … don’t provide solutions,” Mr Albanese told ABC radio.

“They do reflect a view which is expressing frustration that people feel, and we need to respond to that, and we need to respond to it constructively.

“My concern with the rise of One Nation is that they’re a divisive political party.

“Pauline Hanson is a Queenslander who has sought to divide Australians in her approach to politics.

“What I want is solutions, and I’d rather see people from parties of government elected, whether that be in a state election or in a federal election.”

But Dr Manwaring predicted that One Nation was here to stay as Australians shift away from major parties.

“What we’re really seeing, and not just in Australia, is the decline of major parties,” he said.

“Australians don’t identify with major parties in the same way.

“So independent, smaller parties are now a much more prominent part of the fixture, which actually makes Australian politics probably more fluid and fragmented than before.”

During a live debate on Wednesday, both Mr Malinauskas and Ms Hurn warned against voting for One Nation because the party is based in Queensland.

They said that meant One Nation was out-of-touch with South Australia.

“The thing about One Nation is their leader lives in Queensland,” Mr Malinauskas said.

“And when I wake up on Sunday morning, whatever the result of the election is, I’ll wake up in South Australia.

“Pauline Hanson will be in Queensland.”

Ms Hurn echoed his comments, saying that One Nation was “very Queensland-focused”.

“We need South Australian policies on the table because that’s what people are voting for,” she said.

But speaking to reporters on Thursday, Senator Hanson insisted she was across the state’s challenges.

“Health is the biggest issue facing the state,” she told reporters, adding that housing due to “mass migration” was also an issue.

“You’ve got 18 per cent of the children in the state living in poverty. That’s disgraceful.”