Diagnosing victory no mean feat, in suite of 150 contests

THIS election campaign is a national contest where leaders, parties and advertising geniuses do all they can to persuade us to give them our votes. But it is also 150 local contests, where, seat by seat, MPs, rivals and supporters fight it out on home turf.

Twice in seven elections, the party that won on the votes has lost the election because it failed to win the marginal seats. It happened to Andrew Peacock and the Coalition in 1990, and to Kim Beazley and Labor in the GST election of 1998. It could happen again this time.

The polls agree Labor is the clear favourite to win re-election. The bookies also agree: yesterday Sportsbet and Centrebet were offering just a $1.22 or $1.23 return if you successfully bet $1 on Labor to win, but $4 or so if you successfully punted $1 on the Coalition.

You probably agree, too. The latest Age/Nielsen poll found 64 per cent of Australians expect Labor to win, while just 25 per cent tip the Coalition. Even Coalition voters expect their team to lose the election. But a lot can happen in campaigns. And in the end, the result will depend on those 150 separate contests.

Labor's starting position looks strong. It had a 16-seat majority in the old House of Representatives, and now redistributions in most states have shifted a net five seats in its favour. If we vote on August 21 exactly as we voted in 2007, Labor would win 88 of the 150 seats, the Coalition 59, with three independents.

But 33 of those 88 seats are Labor's by narrow margins. A uniform swing of 1 per cent across the board would shift 11 seats to the Coalition, cutting Labor's majority to four. A uniform swing of 1.4 per cent would mean it lost its majority, cutting it to 75 seats, and giving the independents the balance of power. And a uniform swing of 2.3 per cent would mean the Coalition would win a clear majority.

Most elections are close, and this looks like being the same. The battlefield will be wide, opening up more potential for surprise attacks. But two states will dominate the campaign: New South Wales and Queensland. In NSW last time, Labor won 28 of its 49 seats. The redistribution abolished Lowe, but notionally gave Labor three more from the Liberals: Gilmore (with a margin of 0.4 per cent on 2007 voting), Macarthur (0.5) and Greenway (5.7). So it starts with 30 of the 48 seats, the Coalition 16, with two independents.

But its ally, the NSW Labor government, is a huge liability. Last month it lost the Penrith byelection in a 25 per cent swing. That is the same area as the federal seat of Lindsay (which Labor holds by 6.3 per cent) and is near Greenway. So neither seat is safe.

Seven of Labor's seats have majorities of less than 2.5 per cent, mostly in Sydney's outer suburbs where many voters are battling rising interest rates and flat incomes. The bookies see Belinda Neal's old seat of Robertson (0.1) as a goner. They expect the Liberals to retain Gilmore and Macarthur, and probably pick up the Blue Mountains seat of Macquarie (0.3).

They tip Labor to hold Bennelong (1.4), John Howard's old seat, where his conqueror, ex-ABC journalist Maxine McKew, faces former Davis Cup hero John Alexander. The bookies also see Labor holding the north coast seat of Page (2.4), and the central coast seat of Dobell (3.9), despite claims of misuse of health services union funds by MP Craig Thomson.

Surprisingly, the bookies have Labor as a strong favourite in the nation's litmus seat, Eden-Monaro (2.3), which voted for whoever won government at each of the past 15 elections. I suspect it will end up close. The same is true of Sydney. On 2007 voting, a swing of only 5.6 per cent from Labor to Greens would see Housing Minister Tanya Plibersek lose her seat and that's roughly the size of the swings in the polls.

The Coalition also has marginal seats in NSW that could surprise us: Hughes (0.5), Paterson (0.6) and Cowper (1.2). Malcolm Turnbull's seat of Wentworth (3.9) is never safe. But last time Turnbull increased his majority, and his principled stand on emissions trading is likely to see him increase it further.

In 2007, Queensland saw the biggest swing to Labor under Kevin Rudd: a 7.5 per cent swing, nine seats gained, with Labor winning a majority of the state's votes and seats. But now Rudd has been toppled, Labor's hold in is doubt.

The redistribution created a new Coalition seat, Wright (3.8), but moved Herbert (0.0) and Dickson (0.8) into the Labor camp. In Herbert, veteran MP Peter Lindsay decided to draw stumps. In Dickson, shadow health minister Peter Dutton tried to jump ship to the safe seat of Moncrieff, but was thrown back in the water by the preselectors.

The bookies expect the Coalition to win back the central Queensland seats of Flynn (2.2) and Dawson (2.6). It has a good chance in the outer Brisbane seat of Forde (3.4), and the far north seat of Leichhardt (4.1), where former Liberal MP Warren Entsch has come out of retirement to challenge his Labor successor, Jim Turnour. But Labor is tipped to hold on to its other Brisbane marginals: Longman (1.9), Petrie (4.2), Bonner (4.5) and Brisbane (4.6).

In Victoria, Labor won 21 of the state's 37 seats last time, picking up Corangamite (0.9) and Deakin (1.4). They will be its frontline seats in this campaign, with the Liberals confident former ABC TV presenter Sarah Henderson can reclaim Corangamite.

A third Labor seat is in real doubt. In 2007 the Greens outpolled the Liberals in Melbourne and got within 4.7 per cent of unseating Finance Minister Lindsay Tanner. This time, with Tanner going and the latest Age/Nielsen poll showing a 5 per cent swing from Labor to the Greens, the bookies are tipping the Greens.

Labor could win back McEwen (0.0), where retiring Liberal MP Fran Bailey won last time by just 12 votes. But Liberal MP Jason Wood is tipped to hold on to La Trobe (0.5), and Liberal veteran Russell Broadbent looks fairly safe in McMillan (4.8).

A month ago, amid the furore over the mining tax, Labor was looking at a wipeout in Western Australia. Our polling suggested the Liberals would win all 15 of the state's seats. But since then, the leadership change and back-down on the mining tax seems to have brought WA back in line with the nation.

Labor has two marginal seats in Perth: Swan (0.3), which it notionally gained through the redistribution, and Hasluck (0.9). Brand (6.0), south of Perth, looks safe now. The Liberals face a fight to hold two of theirs: Stirling (1.3) and Cowan (also 1.3), while if Labor picks up ground, Canning (4.4) could be within reach.

South Australia, usually a key battleground, looks quiet. Labor now holds all its usual marginal seats by sizeable margins: Kingston (4.4), Hindmarsh (5.1), Wakefield (6.6), Makin (7.7) and Adelaide (8.5). In 2007 the Liberals survived in Sturt (0.9) and Boothby (2.9) by much tighter margins. But these are usually safe Liberal seats.

Tasmania will be interesting. Labor won all five seats in 2007, and the bookies expect it to do so again. But the big swing against Labor at this year's state election suggests that's doubtful. The Liberals are confident of taking back the Launceston seat of Bass (1.0) and the north-west seat of Braddon (2.3).

On state election voting, Labor could also be in trouble in Franklin (4.0) and even Lyons (8.3). And the state voting figures suggest the Greens have a real chance of taking the Hobart seat of Denison, though they will need a 10 per cent swing.

The two seats in the ACT are safe for Labor, as is the outback Northern Territory seat of Lingiari. But the Coalition could take Darwin's seat of Solomon (0.2).

On the polls, Labor will get back with a reduced majority.