From Western Sydney to Western Australia, how marginal is marginal?

Often at the centre of electoral debate, what role do marginal seats have to play in this year’s election? AAP/Stefan Postles

In an election year, perhaps the only thing more inevitable than the major parties’ verbal jousting is the media’s obsession with marginal seats – that handful of bellwether electorates that can supposedly make or break a government.

The Australian Electoral Commission views a marginal seat as one held by a margin of less than 6% — that is, where the Labor or Liberal parties secured 56% or less of the total two-party preferred vote at the last election — and this figure has become almost an article of faith amongst the journalists and commentators who pontificate about campaigns.

But while it’s true that seats held by margins less than 6% tend to change hands more often than seats with roomier buffers, the magical 6% rule is actually fairly useless for working out which seats are really in play this year, for three important reasons.

Swings can be much bigger

According to February’s Nielsen poll, the average national swing against Labor is looking to be somewhere in the order of 7.9%, with some polls suggesting that it may go as high as 12% in parts of New South Wales.

The government is obviously paying attention to those figures, as the prime minister’s recent visit to Western Sydney took in electorates such as Werriwa and Fowler which, at 6.8% and 8.8% respectively, would normally be considered reasonably safe. A precedent has certainly been set for larger swings in recent times, as at the 2012 Queensland state election the average swing against Anna Bligh’s Labor party was 12.9%, while some seats recorded swings as high as 22%. Of course, big swings don’t always go against incumbent governments - the recent West Australian poll saw an estimated average 6.6% swing to Colin Barnett’s Liberals - but it’s a fairly safe bet that any swings this September won’t be working in Labor’s favour.

Seats the AEC says are marginal don’t always fall. Dean Browne

The size of the swing at any single election is influenced by a range of factors, including the popularity of the incumbent government and the perceived viability of their opponents, the scale of the government’s win at the previous election, the effectiveness of parties in pitching their wares during the campaign and the presence or absence of competing events which affect how the parties are viewed (such as the ongoing ICAC hearings in New South Wales).

When the tide is well and truly turning against an incumbent government, seats held by less than 6% may be the first to go but they certainly won’t be the last, and party strategists know this.

For example, my interviews with Liberal National strategists from the Queensland campaign indicate that the party set itself the goal of taking Labor seats with margins of 9% or less. When it became clear during the campaign that this goal was almost certain to be achieved, it then set the more ambitious task of taking seats in the 12 to 13% range and beyond. The LNP’s active targeting of these seats, combined with the electorate’s strong anti-Labor mood, made marginals out of previously safe seats.

The point is that seats with margins much larger than 6% can and do fall when the circumstances are right. Party strategy and the electoral environment are far more important in determining which seats are up for grabs than any single numerical figure.

The point is that seats with margins much larger than 6% can and do fall when the circumstances are right, while seats with much smaller margins are not always defended to the death. Party strategy and the electoral environment are far more important in determining which seats are up for grabs than any single numerical figure.

Swings are not uniform

The 2010 federal election saw an average national swing to the Coalition of 2.58%, but this average masks some big variations in the state-by-state vote. For example, the Labor Party lost far more ground in Queensland, with a swing of 5.9% to the Coalition, while making some gains in Tasmania and Victoria, where it recorded positive swings of 4.4% and 1% respectively.

This kind of regional variation occurs in every federal election, so looking only at average national swings or assuming a uniform threshold would lead us to dramatically underestimate the number of seats under threat in some states, and overestimate the risk to fairly safe seats in others.

To get a real sense of which seats might change hands across the country, we need to consider state-specific polling, demographic factors and past voting history.

For example, the electorates of Canberra and Watson are both currently held by Labor by slightly mroe than 9%, but only one of them has any real chance of falling into the Coalition’s hands come September.

With the exception of one unusual year in the 1990s, Canberra has been held by the ALP since the seat was created in 1974. By contrast, Watson has alternated between Labor and the Liberals over the past 60 years (although it has spent most of the last 30 years in the Labor camp).

What’s more, Tony Abbott has promised big cuts to public sector jobs and spending if the Coalition is elected, which would hit Canberra harder than most other electorates because its economy is heavily reliant on public service jobs and flow-through income.

On the other hand, Watson covers part of this mutinous mass of Western Sydney we’ve been hearing so much about, and so it’s possible that the Liberals’ siren song may fall on more receptive ears there. In short, state and even region-specific factors play a big role in determining how marginal seats really are, so we can’t predict which seats will fall just by looking at the headline national averages.

Swings are like hurricanes

Just as a hurricane annihilates some homes and leaves others untouched, so too can swings affect individual candidates very differently. Australian electoral history is littered with examples of effective, well-regarded local members who bucked big national swings to hold on to low-margin seats, as well as cases where the retirement of a sitting member or a poorly-chosen candidate led to a high-margin seat changing hands.

Regardless of how presidential our political system may have become, local candidates still matter. The member who is well known and well liked around town has a reserve of goodwill which even the most toxic government can’t fully exhaust, so it is always possible for some candidates to stay steadfast in the face of an electoral tsunami.

The flip-side, of course, is that the retirement of well-regarded members can create a vacuum for opposing parties to exploit with their own appealing candidates, which is why Robert McClelland’s seat of Barton and Nicola Roxon’s seat of Gellibrand will be interesting ones to watch on polling day.

So which seats are marginal?

The short answer is that we can’t know with any certainly which seats will change hands until the votes start coming in on 14 September. But by watching where, when and how the major parties are campaigning it is possible to make some informed guesses.

The fact that prime minister Julia Gillard has already been campaigning in Sydney seats with margins between 6 and 10% suggests that, in New South Wales at least, no Labor member with a margin under 10% should take their job for granted.

Personally, I’ll be keeping an eye on seats further up the pendulum too, as if either major party sniffs a serious wipeout, we’ll start to see a lot of activity in seats such as Blaxland, Charlton and Cunningham.

If Labor is feeling pessimistic about its chances, it will probably leave Queensland and Western Australia well enough alone, because it’s hard to see how it could hold low-margin seats such as Moreton, Petrie, Lilley and Blair or pick off Liberal seats like Hasluck and Swan.

The Liberals will need to make up some ground in Victoria, and we’ll learn a lot about how optimistic they are by whether their campaign targets low-hanging fruit such as Deakin and La Trobe, or goes for a Queensland-style victory by picking off seats such as McEwen and Bendigo.

While the 6% rule might satisfy media pundits, any campaigner will tell you the marginal map looks a lot more interesting and complex than that in an election year.

CORRECTION: The original version of this article contained references to the South Australian 2010 campaign that the author has since been informed were not accurate. They have been removed.

Help combat alt-facts and fake news and donate to independent journalism. Tax deductible.