SA Liberals face three major threats in One Nation, a popular premier and independents

The term "triple threat" often has positive connotations, describing a multi-skilled performer, but it also describes what the Liberal Party is facing at the upcoming South Australian election.

On one front, an ascendant Labor government led by popular premier Peter Malinauskas is threatening a swag of Liberal-held seats in Adelaide's suburbs — a political phenomenon that has been well documented and commentated on.

But now two other threats have emerged.

In the upper house, One Nation is positioning itself to capitalise on its federal polling surge to snatch one — but possibly two or three — seats at the expense of the Liberals.

Pauline Hanson's party, which on Tuesday launched ex-Liberal senator Cory Bernardi at the top of its upper house ticket, is vowing to run candidates in all 47 lower house electorates.

While coy on the number of seats the party was realistically targeting, Mr Bernardi said he would "love to be the official opposition in this state".

As one Labor source told ABC News, picking Mr Bernardi was "more of a pitch to the Libs than it is to former Labor voters".

Meanwhile, in the lower house, a handful of local, moderate independents are gearing up for a second crack at unseating Liberal MPs in previously blue-ribbon electorates.

They came perilously close at the last election, and this time will have the benefit of public campaign funding.

These three key threats have emerged while the Coalition's implosion plays out on the national stage and "consumes all the political oxygen in the room for the SA Liberal Party", as one MP told ABC News.

"In every state, the Liberal brand will be damaged as a result of what is going on federally," RedBridge Group pollster and former Labor strategist Kos Samaras said last week.

"The contagion is going to be everywhere.

"[In SA], it's a matter of whether we see an extinction event occur or if we see something a bit less than that."

'Conditions are there for a perfect storm'

The extent of One Nation's support in SA is unclear, but there is enough evidence to sound some alarm bells in Liberal HQ.

A state election poll by Fox and Hedgehog of 1,000 SA voters taken between November 24 and December 5 put One Nation's primary vote at 13 per cent — behind the Liberals at 21 and Labor at 41.

That was well up on the 4.2 per cent One Nation got in 2022, when its first MP Sarah Game was elected to SA's parliament.

Ms Game has since defected to her own party.

Mr Bernardi, a former federal senator of more than 15 years, also brings a far bigger profile than Ms Game, who was relatively unknown before her election.

"Bernardi gives One Nation something it hasn't previously had in South Australia — a credible public face," said Michael Horner, founder of Fox and Hedgehog and an ex-staffer to former Liberal leader Peter Dutton.

"If he and Pauline Hanson can stay aligned while the federal Coalition is divided, the conditions are there for a perfect storm for the SA Liberals."

Mr Samaras said he believed One Nation's vote could double in SA, adding that it was a "live option" the party would outpoll the Liberals in some seats.

"What we know is that when conservative voters, who still were planning to vote for the Liberal Party, when they have a sense that there's no hope, the tendency for them to jump to a party like One Nation is much higher," he said.

"The notion that Malinauskas is absolutely going to romp it home is actually really bad news for the Liberal Party in an environment where One Nation stands in regional South Australia."

He added that while SA was a "moderate state" and One Nation's support was higher in Queensland, NSW and Victoria, that "doesn't mean they [the SA Liberals] don't have a problem".

Give us another look, Liberal leader says

Polling well is one thing, translating that into votes on election day is another.

It was a point Liberal Shadow Treasurer Ben Hood was keen to make on Monday when asked for his thoughts on One Nation's electoral prospects.

"Pauline Hanson isn't the name that's on the ballot paper when it comes to the election, so South Australians would be asking a very clear question — what are they getting from a candidate?" he said, a day before Mr Bernardi's press conference.

"What is their economic policy? How are they paying for all their announcements? There are no costings on the website that I can see."

Unprompted, Mr Hood also offered a criticism of the independents running against sitting Liberals — perhaps an indication they were on the party's mind.

"It really is an unlucky dip: you don't know what you get with an independent, and I think the same can be said for One Nation candidates," he said.

Among the most serious of independent challengers is on the Fleurieu Peninsula, where occupational therapist Lou Nicholson is running again in Finniss after coming within 180 votes of unseating Liberal MP David Basham at the last election.

Ms Nicholson argued that local voters were "disappointed and disenfranchised" with the leadership changes in the state Liberal Party, which has had four leaders in four years.

It is an argument that will be replicated in other regional seats — like Hammond, Flinders and Mount Gambier — where independents are posing serious challenges to the Liberal Party.

New Liberal leader Ashton Hurn, whose only been in the job for a couple of months, argued on Sunday that the Liberals were still the party that would "get the important things right".

"There's no mistaking the fact that we've got a lot of work to do, but I think stability is key in the turbulent times that we're facing as a nation and so I'd encourage people to have another look at the Liberal Party," she said.

If the party's worst fears come true, there might not be much left to look at come April.