The A1 Pizza Bar in Port Pirie delivers more than piping hot pizzas.

Ten years ago this Friday, it delivered government, with the lot, to Jay Weatherill.

On March 22, 2014, a week after a deadlocked state election, the then Labor Premier hopped in a car and fanged off to Pirie where he clinched the critical support of independent MP Geoff Brock to form minority government.

In the night of the long anchovies, the legend is the deal was sealed over a Big Kahuna Pizza.

But when I checked with Weatherill this week, he revealed he ordered the ham and pineapple pizza while “Brockie” and a staffer were in his electorate office printing out the formal details of the deal hammered out that night.

Back at the Brock home, Jay and his team tucked into the pizza with Brock’s partner Lyn Akker.

“We ate most of the pizza and it was cold by the time they got back,” he recalls.

Hold the garlic bread. The Big Kahuna came with a generous side serve – a Ministerial portfolio for Brock in the Labor Cabinet.

On the eve of the Dunstan by-election this Saturday, the 10^th anniversary of the Big Kahuna deal shouldn’t pass unnoticed.

Not just because it was the tastiest way government has ever been secured, some would say stolen, in South Australia.

Nor that in a foodie state fiercely loyal to local delicacies like fritz and frog cakes, a Pirie pizza was the perfect entrée to a game of political show-and-tell.

But because it helps outsiders understand why Labor has been so successful at grabbing government in this state, whether it deserves to or not – and on several occasions over the last 30 years, it really hasn’t deserved it.

The Liberals under Steven Marshall won 53 per cent of the two-party vote in 2014 but were left on the sidelines.

It’s business as usual. For 18 of the last 20 years Labor has ruled this state largely thanks to the support of a rag tag army of conservative independents or straight-out Liberal defectors drawn from the rural or urban fringe.

It’s an incredible fact. In no other Australian state has any political party been happily in office for so long, and with such stability, on the backs of its traditional opponents.

If a conservative MP sides with a Labor Government, do they breach the trust of the people who elect them?

Do we dare ask if they deserve to remain in parliament?

The rot set in when the Liberal MP for Hammond, the late Peter Lewis, threw his support behind Mike Rann so that he could form minority government after the 2002 election – the springboard for the record-breaking 16-years of the Rann-Weatherill governments.

The list of conservative MPs who have backed in or assisted Labor Governments is a long one.

They include Lewis of course, who became Speaker, Karlene Maywald and Rory McEwen who served as “independent” Ministers in Rann’s Cabinets and the big one, former Liberal leader Martin Hamilton-Smith, who sensationally abandoned ship for a Ministerial gig in the Weatherill Government.

Brock is still a Minister in the Malinauskas team, even though his vote has long since been surplus to requirements.

How he manages to sell himself as an independent to conservative voters in his seat of Stuart – he successfully switched from his original Pirie seat of Frome in 2022 – is one of life’s enduring mysteries.

You’d think the Liberals in this state might at some point make the connection between losing their own MPs and losing elections. It’s pretty obvious, isn’t it?

And yet, under former Premier Steven Marshall and now Opposition Leader David Speirs, the party has maintained its perfect track record of accumulating defectors.

Dan Cregan, Fraser Ellis and Troy Bell all quit the Marshall Liberals yet successfully won their seats again as Independents.

Liberal MP Sam Duluk stood as an Independent in his seat of Waite but lost it in 2022 – not to the Liberals, but to Labor’s Catherine Hutchesson.

The latest defector is Nick McBride, now an Independent barely one term after being elected as the Liberal MP for the south-east seat of MacKillop in 2018.

Inexplicably, two senior Liberal MPs have separately told me how happy they are McBride has pulled the pin and how harmonious the party room is without him. They are confident they’ll win MacKillop back in 2026.

Why? Independents have a nasty habit of digging in and holding their seats. Or, as the Waite loss shows, Labor might steal them from under your nose.

It might be nice to have your party room resemble a wellness hug-fest, your dwindling number of MPs sitting on bean bags, holding hands and singing kumbaya, but each defector puts you another seat further from government.

The Liberals will argue they had good reasons to shun MPs who found themselves in a spot of legal bother or embarrassed themselves at a boozy Christmas party.

Maybe so. But what about the McBride’s of this world?

In Tasmania, the last Liberal Premier standing, Jeremy Rockcliff, is staring at defeat in an election this weekend effectively forced by the defection of two Liberal MPs, who quit the party in protest at the government’s support for a new AFL stadium in Hobart.

Now Rockcliff has come up with a cunning plan – a so-called “stability clause” which would, as the ABC puts it, “boot an MP out of parliament if they changed parties or became independent”.

The so-called “stability clause” – bagged as a “Trumpian thought-bubble” – would see an ejected MP replaced by a member of their original party, via a recount.

Because Tasmania has the wacky Hare-Clark voting system with multi-member seats, it would technically be feasible to replace a rogue MP with the party’s next candidate on the list, similar to the way parties in SA fill Senate or state upper house vacancies.

“Similar provisions already exist in other countries like New Zealand, which colloquially refers to it as the ‘waka-jumping law’,” the ABC tells us.

The ultimate test is at the ballot box – if voters are annoyed their MP has changed horses midstream, they can boot them out without the need for a “stability clause”.

But just imagine if SA had a “stability clause” to turf out defectors and replace them with the candidate on the ballot paper who attracted the next highest number of primary votes.

What fun.

A “waka-jumping law” sounds like democracy with extra ham and pineapple. We’d make a meal of it.

And another thing

All the players in this Saturday’s Dunstan by-election are flying blind without their expensive little helpers – internal opinion polls. Or TV advertising.

This is the first genuine marginal seat by-election being fought under the new electoral funding laws introduced by the Weatherill Government.

Similar to AFL salary caps, the legislation imposes strictly audited spending limits on state election campaigns and by-elections.

Parties or candidates are then reimbursed by taxpayers depending on how many primary votes they attract.

In a general election, the legislation sets a global spend of $4.7 million, with caps of $75,000 a seat. Within the cap, parties may juggle the spend seat-by-seat, running up to $100,000 for marginal seats down to $40,000 for safer seats.

But in a by-election, the cap is an inflexible $75,000.

The caps are adjusted for inflation, so in practice are higher now.

This means that in Dunstan, a party must not spend a cent more than $94,482 on their campaign.

With opinion polls costing $20,000 or more depending on the sample size, they blow a big hole in the budget.

So, in Dunstan, the Labor and Liberal camps are eking out the cash on cheap and cheerful campaign tools – and flinging free dirt – instead of polling.

I’m predicting a Labor win in Dunstan.

No pizza in Pirie for getting it wrong. Just a humble pie at Vili’s Café at Mile End.

Matthew Abraham is InDaily’s political columnist. Matthew can be found on Twitter as @kevcorduroy. It’s a long story.