[6] Labor's most notable premiers in South Australia include Thomas Price in the 1900s, reformist Don Dunstan in the 1970s,[9] John Bannon in the 1980s and the factionally nonaligned and pragmatic Mike Rann.

Forty-seven members of the lower house represent single-member electorates and are elected under the full-preference Instant-runoff voting (IRV) system for fixed four-year terms.

[27] At each election, voters choose half of the 22 upper house members, each of whom serves eight-year terms in a single statewide electorate.

However, in a surprise decision, one of the conservative independents, Peter Lewis, decided to support Labor in exchange for holding a constitutional convention, making him speaker of the House of Assembly,[33] and concessions for his electorate including the phasing out of commercial fishing in the River Murray, prioritising the eradication of the branched broomrape weed, changing water rates for irrigation, fast-tracking a feasibility study for a weir and lock at Wellington, and improving rural roads.

[36] However, by this time, Labor had already gained the support of independents Bob Such[37] and Rory McEwen[38] in 2002, as well as Nationals SA member Karlene Maywald[39] in 2004.

Opinion polls indicated that this was likely and ABC elections expert Antony Green said that the "Labor government looks set to be returned with an increased majority".

[57] Martin Hamilton-Smith was considering mounting a leadership challenge, however, he withdrew on 14 October 2005 (probably for the sake of the impression of party unity) and subsequently resigned or was pushed from the opposition frontbench.

[58] One of the most publicised issues prior to the election was the tram extension from Victoria Square to the Adelaide railway station[59] which the Liberals, despite having proposed the idea in their previous transport plan, now opposed.

[67] The Advertiser revealed details of "the biggest project of its kind in South Australia's history", a $1.5 billion redevelopment on the western bank of the inner harbour.

[69] Possible nuclear waste dumps were of concern to many Adelaide residents; Premier Rann successfully lobbied against any federal government proposals.

[71] Tough drink and drug driving laws had also been introduced[72] which included zero tolerance roadside testing for Tetrahydrocannabinol (THC) and Methamphetamine, and later MDMA.

[75] Labor pledged to buy back Modbury Hospital located in the district of Florey, privatised under the Liberal government to alleviate the effect of the State Bank collapse.

[76] The need for homosexual law reform was acknowledged by both major parties, but progress had been delayed, causing disquiet among Labor members.

[77][78] In December 2006, the Domestic Partners bill was passed, providing greater recognition to same-sex relationships on a range of issues such as superannuation.

[90] Labor's wins included the previously marginal Liberal seats of Hartley, Light, Morialta, Mawson, Bright and Newland.

[91] SA Nationals MP Karlene Maywald and independent MPs Bob Such, Rory McEwen and Kris Hanna were all re-elected.

[96] The outer southern suburbs district of Mawson was first won by former Liberal Police Minister Robert Brokenshire in the 1993 state election.

[97] The other outer suburbs district that fell to Labor was Bright, which had been held since 1989 by former Liberal energy minister Wayne Matthew, who decided to retire at this election.

[99] The inner southern suburbs district of Unley was won in 2002 by outspoken Liberal Mark Brindal who failed to win preselection for the seat and moved to contest the marginal Labor seat of Adelaide, but was shrouded in a controversy concerning a sexual relationship that Brindal had with a mentally ill man, forcing him to withdraw.

[102] The inner north eastern suburbs district of Hartley had been won by Joe Scalzi in 1993 and held by a very narrow margin in each subsequent election.

The district has a very high proportion of Italian migrants and the ability to speak the language is considered by many commentators as being vital for a candidate to win the seat.

[103] This was a factor in Labor's preselection of political staffer Grace Portolesi, who defeated Scalzi with a 5.9 per cent two party preferred swing.

[105] Light, which contains Gawler and the outer northern suburbs, was recontested by sitting Liberal member and former Education Minister Malcolm Buckby.

[109] The other Labor seat considered vulnerable was the neighbouring inner city district of Adelaide where high-profile Education Minister and former Lord Mayor Jane Lomax-Smith was challenged by Liberal Diana Carroll.

[2] The Murray Bridge based district of Hammond was won in 2002 by independent MP Peter Lewis who then cut a deal to deliver government to Labor.

The Australian Democrats fell to just one seat in the Legislative Council held by Sandra Kanck, after Kate Reynolds was defeated in her bid for re-election after being appointed in 2003.

The only other contestant had been Isobel Redmond, who ran because she was concerned by some speculation that the Evans deal may have been stitched up by federal Liberal counterparts Christopher Pyne and Nick Minchin.

Previously unknown quantity Ann Bressington, elected on the back of Nick Xenophon's No Pokies popularity, has proposed mainly conservative social policies such as raising the legal drinking age from 18 to 21,[127] zero tolerance of illicit drugs, mandatory twice-annual drug tests of every school student over the age of 14 regardless of whether parents give their consent,[128][129] and making the sale of "drug-taking equipment" illegal.

[132] Setting a precedent, Sandra Kanck's pro-euthanasia speech which contained suicide methods was censored from the internet version of Hansard in August 2006 as a result of an upper house motion, with Labor, Family First, Nick Xenophon and Ann Bressington voting for, and the Liberals and SA Greens member Mark Parnell voting against.

A record-breaking 13-hour Parnell-Bressington filibuster occurred in May 2008 in crossbench opposition to WorkCover cuts being passed by the major parties due to the increasing underfunded liability in the workers' compensation scheme.