With one federal and three state elections in the offing, 2010 looms as the most event-packed year on the electoral front in recent history. As far as timing is concerned, the only wild card in the deck is the federal election. Kevin Rudd could use the emissions trading scheme trigger to call a double dissolution election at any time, although doing so in the first half of the year would commit the government to a highly problematic half-Senate election no later than mid-2012. Less troublesome would be a double dissolution later in the year, which would have to be held no later than October 16. A normal House of Representatives and half-Senate election could be held at any time from August 7, and could legally be delayed until as late as April 2011 next year — although it most assuredly won’t be.

Barring extraordinary circumstances, no such uncertainty surrounds the state elections. Victoria’s fixed term legislation sets the date for the last Saturday in November, which will be the 27th. South Australia likewise has a fixed election date of March 20. Tasmania does not have fixed terms, but Premier David Bartlett has announced the date well in advance — annoyingly also for March 20, setting up a repeat of the two states’ simultaneous elections in March 2006.

Today’s lesson concerns South Australia, for which I have just published my seat-by-seat election guide. Mike Rann’s rise to power after the February 2002 election completed Labor’s clean sweep of state and territory governments, which remained intact until the Carpenter government’s defeat in Western Australia in September 2008. The Rann government’s electoral fortunes since have followed a familiar pattern. It came to power as a minority government when conservative independent Peter Lewis made a shock post-election decision to throw his lot in with Labor, after saying during the campaign that any talk he might do so was “sleazy nonsense”. Faced by a fracturing Opposition under the indecisive leadership of Rob Kerin, Rann brought home the bacon at the 2006 election, picking up a 7.7% swing and winning six seats from the Liberals.

The trajectory of first-term minority government to landslide re-election had earlier been followed by Labor in Queensland (elected 1998, re-elected 2001) and Victoria (1999 and 2002), and was partly reflected by NSW Labor’s experience in winning a one-seat majority in 1995 followed by a resounding win in 1999. In each case Labor went on to win only slightly less emphatic third victories. While the polls suggest the Rann government will be re-elected (the most recent Newspoll gave it a 53-47 two-party lead), it seems unlikely it will do so in quite as fine style as Bob Carr in 2003, Peter Beattie in 2004 or Steve Bracks in 2006.

While poll respondents have strongly indicated they will not let the Michelle Chantelois allegations influence their vote, the issue is an electoral negative if only because the looming court cases threaten to distract Rann in the early part of the next term. The issue is also feeding into perceptions he will not see out the next term, taking some of the shine off his personal vote-pulling power. With no clear heir apparent in place, it also raises the prospect that ministers’ energies will be diverted into jockeying for the succession. Most importantly, Rann will not enjoy the electoral gift of a long-serving and increasingly unpopular coalition government in Canberra.

The Liberals by contrast have stumbled almost by accident on a leader whose Newspoll approval rating for October-December was 51% — the best result for a South Australian Opposition leader in 17 years. As Antony Green demonstrates, voters don’t really get to know Opposition leaders until an election campaign. If Isobel Redmond really is as saleable as her 33% net positive rating makes her appear, and if she and her party can run a sufficiently tight ship, a lot of the 31% who profess themselves undecided about her will break her way during the campaign — and many will jump on the Liberal bandwagon in doing so.

For all that, the odds remain stacked in Labor’s favour. It would take the loss of five seats to cost it its majority, and most likely six to cost it government given that one of the three cross-benchers is Labor-turned-Greens-turned-independent member Kris Hanna. In the context of South Australia’s compact 47-seat House of Assembly, that represents a considerable hurdle for the Liberals, who will need an overall swing of about 7%.

The two pieces of low-hanging fruit are the seats of Light, based on Gawler just to the north of Adelaide, and Mawson, which consists of outer southern suburbs plus the McLaren Vale wine-growing area. Both are naturally conservative seats that are very likely to return to the fold.

Interestingly, the next four seats up the pendulum are the eastern suburbs neighbours of Norwood, Newland, Hartley and Morialta, which can brace themselves for some heavy-duty pork-barrelling in the weeks to come. The 3.7% margin in Norwood looks surmountable, but the seat recorded an unusually small swing to Labor in 2006 due to the popularity of the Liberal candidate, former Adelaide Crows star Nigel Smart. With a considerably lower-profile entrant this time around, its natural margin would be at least 6%.

Even more problematic is Newland (5.2%), where the Liberals have scored an own goal by endorsing Trish Draper, the federal member for Makin from 1996 until her retirement in 2007. Draper continues to carry the baggage of an episode in 2004 when she was accompanied at taxpayers’ expense by her then boyfriend Derick Sands on a study trip to Europe. While she just managed to retain Makin at the 2004 election, she did so in the face of the biggest swing to Labor in the state — a woeful result for an electorate so heavily stacked with mortgage payers. Far from being forgotten, this episode made a return to the front pages last year, when Sands lost a defamation case he pursued against Channel Seven and the ABC over reports he had been identified as a suspect in a murder investigation.

In Hartley (5.6%), the Liberals have made the less-than-inspiring decision to re-nominate Joe Scalzi, the long-term back-bencher who lost the seat to up-and-coming Labor member Grace Portolesi in 2006. Despite the relatively higher margin, the Liberals probably have more reason to be optimistic about Morialta (6.8%), where incumbent Lindsay Simmons faces former Young Liberals president and Christopher Pyne staffer John Gardner. The only other seat with a margin that would normally be considered surmountable is Bright, located on the coast south of Glenelg around Brighton, where Labor member Chloe Fox has achieved an impressive electoral track record.

If the Liberals are to fall short in more than one of the seven aforementioned seats, they will need to make up for it with a freakish double-digit swing in Adelaide (10.5%) or Florey (12%). The government has been very mindful of the significance of the former seat in particular, making several contentious policy decisions relating to the city centre with a view to protecting its member, Jane Lomax-Smith.

Further up the pendulum are several  Adelaide seats that normally lean moderately to Labor, where margins were engorged in 2006 by an Adelaide-wide swing of about 9%. Even if the momentum the Liberals have been building in recent polling continues, they appear to be at considerable risk of achieving their biggest swings in these seats, where Labor can afford to take the hit.