KEY POINTS:
CANBERRA - Living life on the edge is not much fun if your job depends on the whim of a relative handful of voters.
Ask Malcolm Turnbull, Australia's Minister for the Environment and Water Resources, whose one-time blue-chip Liberal seat in Sydney's silvertail suburbs is a now a political nightmare hanging on the thinnest of threads. Or even Prime Minister John Howard, whose Sydney stronghold of Bennelong has been shattered by a demographic earthquake that pollsters now say could deliver it to Labor.
This is war at the margins, where fighting will be fiercest.
Labor leader Kevin Rudd, needing 16 extra seats to win power, will besiege the Coalition's 35 most vulnerable seats, while fending off Government assaults on the 11 marginal electorates his party clings to by wafer-thin majorities.
Neither can afford to lose the war of the margins. While broad national polling predicts a Labor victory by a landslide if the consistent run of poll results accurately reflects the final vote the detail of the election is a far more complex beast.
Each state is different, for a start.
Bolstered by the mining boom, huge wages and generous conditions, Western Australia is the one state that looks safe for the Government. The Coalition and Labor each have two marginals at stake there.
Queensland, where Newspoll says Labor leads by a slim margin of about 5 per cent of the total two-party preferred vote, is less certain. The two-party vote is the decider in Australian elections under the preferential voting system, in which the descending order of preferred candidates is distributed among contesting parties.
Polling by Newspoll indicates that on a state-wide basis, Labor enjoys a commanding lead in New South Wales and Victoria.
Within this complex there are marginal seats whose composition, volatility and voting patterns provide microcosms of national trends. Australians call these bellwether seats, after the trained sheep wearing bells which lead a following flock usually to destruction in an abattoir.
Two are prominent for analysts: Bass in Tasmania, and Eden-Monaro in NSW. Historically, whoever has won these seats had also won power.
Bass, and the neighbouring electorate of Braddon, are of particular interest this election because of the Government's decision to approve a new pulp mill in the environmentally-sensitive Tamar Valley above Launceston in the north of the island.
While anger has soared on mainland Australia including opposition in Turnbull's razor-edge electorate of Wentworth, Tasmanians tend to dig in their heels and welcome developments that will boost the local economy.
The blundering attempt by former Labor leader Mark Latham to lock up Tasmanian forests in the last election resulted in unions publicly embracing Howard. This time round Rudd has imposed strict party discipline, supporting the decision. Thus Tasmania is a neon-bright question mark.
Eden-Monaro bulges around Canberra and extends to the south coast of NSW in one direction and the Snowy Mountains in the other. The electorate embraces just about every contradictory position in Australian politics: environment versus tourism and forestry on the coast; drought, agriculture and regional priorities in the centre; and alpine disputes in the west.
In major cities where Labor holds the advantage, social evolution and demographic tsunamis are shaking former historical certainties. Along the continent's coasts, and especially in the northeastern sunbelt, the baby boomer seachange is reshaping political landscapes.
After the 2004 election the Australian Electoral Commission studied growth in population and redrew significant electoral boundaries in NSW and Queensland. This diminished the Government's chances of holding the Sydney seats of Parramatta, Howard's Bennelong, Turnbull's Wentworth, and the Queensland electorates of Moreton, Blair, Bowman, Dickson and Hinkler.
Howard has 35 marginal seats to defend: five with a majority of less than 1 per cent and 11 with 5 per cent or less. But Australian voters are conservative and above all addicted to affluence. Rudd must convince them that a Labor Government will not harm them and, more, that life will be even better.
