If Labor picks up the seat of Fisher, as widely expected, it will not only give the party an outright majority in Parliament – it could also turn the southern suburbs seat into a Labor stronghold for the long-term.

There’s a long way to go, but the power of incumbency could give Labor a firm grip on this presumed conservative-leaning seat.

Just as Labor’s Leon Bignell used grassroots campaigning to turn the marginal neighbouring district of Mawson into a relatively safe seat, Nat Cook has the community credentials to do the same in Fisher.

This scenario would be a nightmare for the Liberals, who are still scratching their heads about how they failed to win the state election, despite a significant advantage in two-party terms.

Despite a raft of terrible local cost-of-living issues for Labor, the Liberals couldn’t shift their primary vote in the weekend’s by-election, which is looking like a Labor win with pre-poll and postal votes left to count.

READ MORE: Fisher votes – Libs draw closer

In a broad sense, not one of late MP Bob Such’s primary votes shifted to the Liberals, despite the fact he was presumed to have a Liberal-leaning voting base.

Labor, the other hand, attracted a swing of about 9 per cent.

This is an unprecedented result in Australian politics for a fourth-term government.

While both sides of politics accept that federal issues were at play – particularly Defence Minister David Johnston’s slight on ASC workers – there are four key reasons why the Liberal campaign went so badly.

The federal factor

State Liberals are “white hot” with rage about the missteps by their federal colleagues, according to Liberal sources.

While the Abbott Government is clearly on the nose, it was the substance of Johnston’s contribution to the debate that worried voters – and sent them into Labor’s arms.

Research from both major parties in Fisher shows that job security was the key concern – not the cost of living. Without a job, you can’t pay a bill of any size.

Labor plastered polling booths with images of Abbott and references to Johnston’s claim that he wouldn’t trust ASC voters to “build a canoe”. It finished with the kicker: “Don’t trust the Liberals. Vote for local jobs. Vote Labor”.

The Liberals spent the first part of the campaign focusing on Labor’s hike to the emergency services levy and criticisms of water pricing (before switching focus to independent candidate Dan Woodyatt).

Labor focused on jobs and pushed Nat Cook as a voice for the community.

Federal and state Liberals have been lining up to admit that the Abbott Government’s shocking fortnight was to blame.

But this result is unprecedented, even if the Liberals can pull off a miracle and win from here.  No-one can recall a fourth-term government achieving anywhere near this sort of result in a by-election.

The worry for state and federal Liberals is that a Labor Government presiding over high debt and relatively high unemployment managed to gain a swing by campaigning on the issue of jobs.

If the community doesn’t believe the Liberal Party has the edge on Labor in terms of jobs and economic growth, the Liberals are in serious trouble indeed.

Labor has more foot soldiers

Grassroots campaigning has become crucial in state elections – and it is even more important in by-elections.

The March state election showed the power of foot-soldiers in the field, with Labor winning a raft of marginal seats with the help of their army of rusted-on volunteers.

Young Labor was mobilised in force in Fisher, and outnumbered the Liberal volunteers significantly on the ground.

Flinders University political scientist Haydon Manning suspects this team gave Labor an edge, as Young Labor did in the ALP’s victory in the Victorian election.

The volunteers door-knock with the specific purpose of reinforcing key campaign messages.

“It’s all about personal contact – delivering the message personally,” he says.

Labor selected the right candidate

Nat Cook is a respected member of the Fisher community. She lives in the electorate – unlike her two key opponents – and has deep links with sporting clubs and other groups in Fisher.

She’s known for her work with the Sammy D Foundation – named after her son who was killed in a one-punch attack.

Attacks on her credibility by Family First MLC Robert Brokenshire are likely to have backfired, particularly given the local distaste for the negative campaign against Bob Such in the lead-up to the March state election.

As Premier Jay Weatherill noted this morning, the attacks made Cook seem “almost like an independent candidate even though she was a Labor candidate”.

As Manning says, Cook didn’t have the pedigree or feel of your typical Labor candidate, who usually comes up through the union movement and the party.

She seemed an authentic local and doorknocked by herself or with volunteers.

By contrast, the Liberal candidate Heidi Harris is a long-term Liberal staffer and was often seen campaigning with Liberal shadow ministers.

The Woody factor

From a standing start, the enigmatic independent Dan Woodyatt achieved a respectable primary vote of 22.5 per cent.

He didn’t direct preferences, but about two thirds of his preferences flowed to the Labor Party.

More than this, he became a distraction for the Liberal campaign.

After campaigning hard on Labor’s cost-of-living problems, the Liberals became spooked by Woodyatt’s competent campaign, and turned their attention to him.

A slew of negative mail-outs – including one that was slapped down by the Electoral Commissioner – took focus away from Labor’s cost-of-living hikes.

What now for Steven Marshall?

Marshall is about to face the media today, and he’s no doubt under pressure.

However, the Liberals can be expected to remain behind him, at least until after the Davenport by-election in late January – a contest that Labor will now attack with renewed vigor.

He can also be expected to adopt a bolder strategy, particularly in distancing himself from the increasingly unpopular Abbott Government.

In the party, he will point out that while the by-election swing to Labor is unprecedented, the unpopularity of Abbott is also reaching historically disastrous levels.

A Fairfax/Ipsos poll out today shows that Abbott’s personal standing has fallen to the degree that voters view him as incompetent and untrustworthy as Julia Gillard at her most unpopular.

Labor, in its dark Gillard/Rudd days, seemed unelectable at any level of government.

The hope for Marshall is that – as history shows – politics can change very quickly.