The result of the recent South Australian election was clear with Labor the biggest winner, the Liberal Party the biggest loser, and Pauline Hanson’s One Nation the big improver.
In the aftermath Labor can bask in its massive majority and the smiting of its political opponents.
Division on the other side of politics eased Labor’s path to re-election, but the strong performance of One Nation in Labor’s safest seats has delivered Labor a serious warning.
Hidden in the detail of the results is that One Nation turned Labor’s side of the electoral pendulum upside down. Liberal seats and Labor’s most marginal seats swung to Labor, but many of Labor’s safest seats swung strongly to One Nation.
Much of this comes about because the South Australian election was not a two-party contest. Only 13 of the state’s 47 lower house seats finished as Labor-Liberal contests. The majority of seats, 25, finished as Labor-One Nation contests.
The result is the Electoral Commission of South Australia (ECSA) has abandoned past practice of undertaking alternative two-party preferred counts in contests that weren’t Labor-Liberal finishes. In 2026 the Commission will do a two-party re-count in seats where Labor did not make the final pairing, but in every other seat report a count that is Labor versus whoever finished second.
In the past there has been Coalition criticism of academics for analysing Australian elections as Labor versus Non-Labor. For the 2026 South Australian election, there is no other alternative.
It creates a post-election pendulum that is a mix-and-match of party contests, perhaps a portent of where Australian politics is heading. All swings since 2022 will compare a Labor-Liberal finish with whatever pairing is produced for 2026.
Which is where the Labor-One Nation swings in safe seats are startling. Sometimes a change in final pairing can create an artificially large swing caused by the vagaries of exclusion order and unexpected preference flows.
That’s not the case in South Australia. The two-candidate swing against Labor with these mix-and-match results correlates with the decline in Labor’s primary vote and the rise in support for One Nation.
The chart below shows the relationship between Labor pre-election margin and 2026 swing. Labor’s safest seats are to the right of the chart, and the array of points below the horizontal axis show how many of Labor’s safest seats swung strongly towards One Nation. The blue points for Labor-Liberal contests are all to the left and show a clear pattern of swings to Labor. But the swing against Labor increases as Labor’s pre-election margin increases.
The swing was to Labor in areas where the Liberal vote held up, but against Labor where the Liberal Party slipped to third and the swing is measured against One Nation. And this swing is heavily correlated with the decline in Labor’s primary vote and strong support for One Nation.
In safe Labor seats, there was a switch in primary vote from Labor to One Nation. There are safe Labor seats in northern Adelaide where One Nation polled above 30%, levels the Liberal hardly ever achieves.
The trend in the above chart stands out as starkly in the tables below which aggregate results for Labor seats based on pre-election margin. Labor came out of the election with a higher primary vote and after preferences vote in the seats it defended on margins under 15% than it recorded in the seats with margins above 15%. There was a 5.9% swing to Labor in seats with margins under 15%, but 6.7% away in very safe seats with margins above 15%.

Again, this is a mixed swing based on One Nation replacing the Liberal Party as the second placed in seats. But the swing occurred on primary votes as well as two-candidate preferred votes, so its not an artifact of the change in final pairing.
At a normal election both the above tables would swing in the same direction. But in South Australia in 2026, marginal seats swung to Labor and very safe seats against Labor. The seats of Elizabeth, Light and Taylor had margins above 19% before the election, but after the election are three of Labor’s four most marginal seats under 5%.
There’s more on the results inside the post with a link to a draft analysis I’ve prepared. It includes results for all seats, tables of preference flows and a new electoral pendulum.
But I’ll start with some comments on the looming Farrer by-election.
Read More »SA2026 – huge win for Labor but a warning in the result