On Elections

How people elect parliaments

South Australian election 2018: preview

Australia may be headed for an historic upset of its traditional two-party election dynamic at the election of the State parliament in South Australia on March 17.

For decades the nation’s leading parties, the centre-left Labor party and the Centre-right Liberal party, have alternated in office in the state, as they have done at the national level.

South Australia also has a tradition of moderate separatism from the Liberal party. A national centrist Australian Democrat party, which had part of its origins in moderate South Australian liberals, existed from the late 1970s until the turn of the century.

Now a new centrist party founded and led by independent former state MLC and national senator Nick Xenophon is turning the election into a real three party race.

Opinion polls are consistently showing Xenophon’s newly founded SA Best party polling above 20% across the state.

The South Australian House of Assembly consists of 47 members elected by preferential voting in single member electoral divisions (the standard Australian electoral model for lower houses other than for the state of Tasmania and the national capital Territory). The voting system is the same as that known as the Alternative Vote (AV) in Britain and Canada, or instant runoff voting (IRV) in the US, and has been used in Australia for around a century.

Normally in these Australian elections the flows of vote preferences from voters supporting minor parties and independents will transfer to either of the two major parties. In close elections this can determine which of the major parties gains a majority of the parliamentary seats.

But if SA Best candidates can manage to place second in their electoral division, the preferences from voters backing the major party which placed third may be sufficient to elevate them to become the seat winners.

If SA Best achieves a general electoral result of around 28% statewide, it could well leverage the centrist preference advantage into a very large number of seats.

Australian electoral analysts, normally capable of accurate predictions of preference flows, are struggling to get meaningful polling data to predict what preference splits will happen in each of the three supporter bases in the electorate. Preference flows from voters supporting the traditional minor parties – the Greens and Christian conservatives (the latter usually being significant in South Australia) will further complicate predictions.

image - South Australian House chamber

The chamber of the South Australian House of Assembly (image: Parliament of South Australia)

The possibility of a very strong result is even causing speculation that Xenophon could end up as the state Premier. If so, he would be the first Australian head of government from a party other than Labor or Liberal (or its predecessors), or the Country/National party in Queensland, since around 1910.

South Australia’s boundary redistribution system is also a cause of controversy. The system officially attempts a form of well-intentioned gerrymandering to try to correct for the state’s unusual electoral demographics.

Large numbers of the state’s conservative voters are concentrated in the rural electoral divisions. Meanwhile the electoral divisions in and near the state capital Adelaide, which makes up around 75% of the state population, are more closely politically balanced.

The situation has allowed the incumbent Labor government to win three of the past four elections even though the Liberals have been found to have a majority of the aggregated ‘two-party preferred vote’ – a statistic which Australian electoral officials calculate after elections.

To address this phenomenon, non-partisan officials deliberately redraw the state’s electoral division boundaries between every poll, using the previous election’s results to try to create a situation where a major party winning a majority of the two-party preferred vote would result in them winning a majority of the seats.

But the effort has failed to work at every close election where it was relevant (decisive election wins by Labor render the boundary-drawing effort irrelevant).

The SA mechanism is a unique case of a legislated, state-sanctioned and nominally well-intentioned electoral boundary manipulation. But leaving aside the problem that it requires manipulation of the representation rights of local residents in many locations, it has never once proved effective in getting the ‘right result’ in a close election.

Nonetheless, the new boundaries drawn for the 2018 election were thought to require the incumbent Labor government to achieve a 3% swing to simultaneously reach 50% of the statewide two-party preferred vote and also retain a majority of seats.

But the rise of a clear third party in SA Best will entirely demolish the aims of the boundary manipulation law. Even the notion of the two-party-preferred statistic will itself be rendered meaningless by a three-party result.

The most recent polls are being interpreted to indicate a slight easing of support for SA Best, although it is still tracking above 20% statewide.

But there are not enough polls being taken to reveal more than snapshots of the mood of the South Australian electorate. Moreover volatile support for new parties – and for degrees of public rejection of incumbent parties – has proved difficult to accurately poll worldwide in the past few years.

If the incumbent Labor government loses its majority to a three-party outcome, it would stay in office until the other two parties in the House united to vote it out.

But in the context of a dominant national two-party culture, the two established major parties will both be determined to strangle any rival third party at birth.

National election analyst for the public broadcaster ABC Antony Green will as usual be following the state election closely.


More reports: 

An excellent summary of the situation by Ben Raue in The Guardian: Can Nick Xenophon end two-party politics in South Australia? (20 February)

3 comments on “South Australian election 2018: preview

  1. AlexJ
    February 20, 2018

    “If so, he would be the first Australian head of government from a party other than Labor or Liberal (or its predecessors) since federation in 1900.”

    I believe several Queensland Premiers would beg to disagree…

    For those readers not familiar with Australian politics, the Liberal Party usually governs in Coalition with the National Party [formerly called the Country Party] whose MPs represent much of rural and regional Australia.

    Queensland has a higher share of its population outside the capital metropolis, so our Nationals were at times the senior partner in the Coalition at a state government, and at one point in the 1980s even had a majority of MPs in their own right. This was helped by a pro-rural malapportionment.


    With removal of the malapportionment and a soaring metropolitan population, Queensland’s electoral geography has since changed; it is now a necessity for the conservatives to be reasonably appealing to urban voters.

    Due to a quirk of history, the urban Gold and Sunshine Coast seats continued to be held by Nationals.

    This presented a poser, because the Nationals rarely contest those seats, and hence when the coalition parties are in Opposition, the Nationals often had a majority of the coalition MPs, but in Government the Liberals would have the majority of coalition MPs. Eventually the parties amalgamated, and hence today we in Queensland have the Liberal National Party.

  2. Malcolm Baalman
    February 20, 2018

    Yes, fair point about the Queensland Country/National party … text of the post revised a little. Of course the Country party and the Liberals – the two are now merged – together constituted the conservative anti-Labor force. The two did often compete for the same seats, but preferencing made that workable.

  3. Pingback: Unusual Australian elections will highlight role of preferential voting | On Elections

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This entry was posted on February 20, 2018 by in District boundaries, Gerrymandering, South Australia, Uncategorized.
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