In
1973, Labor retained office with 54.5 percent of the two-party vote, and the LCL became the
South Australian division of the Liberal Party of Australia in 1974. Labor retained power in
1975 with a majority of seats but lost the two-party vote on 49.2 percent. Dunstan then instituted "one vote one value" electoral reform, which meant that all seats had to contain approximately the same number of enrolled voters; and created an independent body, the South Australian Electoral Districts Boundaries Commission, to draw the electoral boundaries. After
John Bannon won in
1989 even after losing the two-party vote at 48 percent, a
1991 referendum was passed which added a "fairness clause" to electoral legislation, requiring the commission to redistribute seats with a view toward ensuring that party which receives a majority of the statewide two-party vote at the forthcoming election should win the two-party vote (in terms of "traditional" two-party matchups between Labor and the Liberals) in a majority of seats. Despite this 1991 change, Labor has won a further three elections (
2002,
2010 and
2014) with less than 50% of the two party preferred vote; though in 2002 this was due to the support of independents (and also initially in 2014, until Labor's
Nat Cook won the
2014 Fisher by-election soon after). Prior to the
2018 election, at which the Liberals won a majority, Labor had been in office for all but 12 years since 1970, the Liberals having only governed from
1979–
1982 and
1993–
2002. Since the end of the Playmander, South Australian politics have been characterised by a concentration of seats in the Adelaide metropolitan area, a manifestation of South Australia's status as the nation's most centralised state. Successive redistributions have resulted in Adelaide and its suburbs containing close to three-quarters of the seats (34 out of 47 in 2017). This makes it difficult to form even a minority government without gaining significant ground in Adelaide. Labor's success in South Australia over the last four decades has been built on a strong base in Adelaide; under normal conditions Labor wins the most seats in the capital. Since the 1975 redistribution, most of the Liberal margin has been locked into ultra-safe rural seats. This remained the case even after the "fairness clause" amendment. In 1979, for instance, the Liberals won 55 percent of the two-party vote–the first time in 20 years that the non-Labor side in South Australia had won a majority of the two-party vote while also winning the most seats. However, they only won 25 seats—a bare majority of two—mainly due to winning only 13 seats in Adelaide. That narrow majority was reduced even further to 24 seats after the Liberal victory in Dunstan's old seat was overturned, and Labor won the ensuing by-election. Thus, despite having won by a margin large enough for a landslide victory in the rest of Australia, the Liberals only governed on a knife-edge. In
1989,
2010 and
2014, the Liberals won a narrow majority of the two-party vote. However, the Liberals fell short of winning government in all three elections because most of their majorities were wasted on massive landslides in their rural heartland. The only comprehensive Liberal victory, in terms of both two-party vote and seat count, came in 1993, when the Liberals won 61 percent of the two-party vote and all but nine seats in Adelaide en route to the biggest majority government in the state's history. The 2010 and 2014 elections illustrated how difficult it is to form government in South Australia without a strong showing in Adelaide. In 2010, the Liberals picked up a swing of 8.4 percent, more than the uniform 6.9 percent swing that the Boundaries Commission envisaged as being enough for a Liberal win. However, most of that swing came in seats that would have stayed in Labor hands in any event; while 22 seats saw double-digit swings, Labor sat on insurmountably safe margins in 16 of them. Additionally, while the Liberals took three Adelaide-area seats off Labor, they only won six additional seats in the capital. While six of the Liberals' 13 safe two-party seats were in Adelaide, all but one of their four marginal seats were urban. As a result, while the Liberals won 51.6 percent of the two-party vote, Labor was still able to eke out a two-seat majority. In 2014, the Liberals won 53 percent of the
two-party vote to Labor's 47 percent. However, in Adelaide, Labor won 51.5 percent of the two-party vote to the Liberals' 48.5 percent. The Liberals only won 12 of Adelaide's 34 seats. While only four of their 14 safe two-party seats were located in Adelaide, all eight non-safe (<10 percent) seats were in Adelaide. Overall, the election resulted in a
hung parliament with 23 seats for Labor and 22 for the Liberals. The
balance of power rested with the two
crossbench independents,
Bob Such and
Geoff Brock. Such's seat of
Fisher and Brock's seat of
Frome would have had decisive Liberal majorities in "traditional" two-party matchups in 2014. Counting the seats won by the independents, 24 seats returned Liberal two-party votes and 23 returned Labor two-party votes, so the requirements of the "fairness clause" were met. Such did not indicate who he would support in a
minority government before he went on two months' medical leave for a
brain tumour which he would die from in the ensuing months. Brock subsequently supported Labor., allowing Labor to form government by one seat. It is the second time that Labor has won four consecutive state elections in South Australia, the first occurred when Dunstan led Labor to four consecutive victories between 1970 and 1977. Labor achieved
majority government when
Nat Cook won the
2014 Fisher by-election triggered by Such's death. After 16 years in office–a record for a Labor government in the state–Labor was defeated at the 2018 election by the Liberals under
Steven Marshall. Even then, the Liberals suffered a state-wide swing against them and were only able to win 25 seats–as in 1979, a bare majority of two. They did, however, manage to win 16 of the 33 metropolitan seats, their best showing in Adelaide since the 1993 landslide–thus proving that it is very difficult to win even a minority government without a strong showing in Adelaide. The Liberals were thrown from office in a massive swing in
2022 after seven of their metropolitan seats fell to Labor under
Peter Malinauskas.
Four years later, the Liberals were reduced to their smallest-ever presence in the House of Assembly, a rump of five seats, after only winning two seats in the capital. One element of the Playmander still exists to this day – the existence of single-member seats. Each Labor period of government since the end of the Playmander had at least one comprehensive win (1977, 1985, 2006, 2022 and 2026) allowing often-Liberal seats to be won by Labor candidates who then built up
incumbency and personal popularity. Examples in 2014 were
Mawson,
Newland and
Light, and additionally in 2010,
Bright and
Hartley – all gained at the
2006 election landslide. Mawson in fact swung toward Labor in
2010,
2014 and
2018 despite the statewide trend. The
bellwether seat of
Colton was retained by Labor. Furthermore, metropolitan Liberal seats and polling places had single and double digit swings against them. By comparison, as mentioned above, there has been only one comprehensive Liberal win since the end of the Playmander, in 1993. In 2014, referring to the 1989 fairness legislation, Weatherill responded to Liberal complaints about the fairness clause by saying, "Complaining about the rules when you designed the rules I think sits ill on the mouth of the Liberal Party." Electoral Commissioner
Kay Mousley said it was an "impossible" task for the Boundaries Commission to achieve the legislated requirement, stating "It is a constitutional requirement, and until the constitution gets changed, I must say I find it a very inexact science". Additionally, she had previously stated in 2010, "Had the Liberal Party achieved a uniform swing it would have formed Government. The Commission has no control over, and can accept no responsibility for, the quality of the candidates, policies and campaigns."
University of Adelaide Professor of Politics Clem Macintyre stated after the 2014 election that fair electoral boundaries are an "impossible challenge". ==Results 1933–1973==