South Australian state politics received a palpable shock six weeks ago when Newspoll produced a stellar result for Nick Xenophon. His new party, SA Best, scored 32 per cent of the primary result (among the 800 people polled), with the Liberals trailing on 29 per cent and Labor on 27 per cent. Perhaps less surprising was the popular endorsement of Xenophon as preferred premier (46 per cent), much higher than incumbent Jay Weatherill’s 22 per cent and Liberal leader Steven Marshall’s 19 per cent. The figures signalled that Xenophon and SA Best are now the third major force in the state.

That was just one poll, though undoubtedly a striking one. A more recently released Essential survey, aggregating data from October to December, put SA Best’s primary vote quite a bit lower, at 22 per cent, with Labor on 34 per cent and the Liberals 31 per cent. That’s close to the average of more than a dozen polls during 2016–17 (excluding the December one), which gave Xenophon a primary vote of 21 per cent. But even on those figures, SA Best will play a major part in the March election. Xenophon has indicated that the party will field up to twenty candidates, heightening the prospect of SA Best’s being the kingmaker, or even part of a coalition with one of the majors.

What explains the rise of SA Best? One key factor is the evident decline in Australia’s two-(and a half)-party system. It’s easy to forget how dominant the major parties once were: at the 1951 federal election, Labor and the Coalition scooped up 97.9 per cent of the primary vote; by 2016 the combined figure was 76.5 per cent, the lowest since the second world war.

The pattern is similar at the state level. In South Australia, the majors were picking up over 90 per cent of first preferences in the 1960s and 1970s. By the 1990s and 2000s, the figure was about 80 per cent, with minor parties and independents collecting the rest. At the last state elections in New South Wales and Victoria, non-majors received a shade under a fifth of the vote (Victoria) and a shade over a fifth (New South Wales). Xenophon is clearly speaking to a wider disenchantment.

But that’s only part of the story. It doesn’t tell us why a “centrist” challenger hasn’t emerged elsewhere. And it doesn’t explain why very few minor parties, with the exception of One Nation in Queensland in 1998, have broken through in the state and territory lower houses. Xenophon’s popularity also has specifically local dimensions.

Nick Xenophon is commonly (and in some cases critically) described as a populist. A search of newspapers over the past twelve months reveals 106 articles linking his name with the term “populist.” One experienced SA journalist, Tory Shepherd, goes further, describing Xenophon as a “master of populism.”

But it’s important to remember that populism has a specific meaning in political science, coupling a strong anti-elite rhetoric with direct appeals to “the people” or “the heartland.” Xenophon might present as an outsider, but part of his appeal is his search for “popular” rather than “populist” policies. His breakthrough in 1997 at the state level came on a shrewd “no pokies” ticket, building support on an issue that was neglected by the majors.

Throughout his career, in fact, he has had a canny political antenna for eye-catching and high-profile issues, from windfarms to accusing a Catholic priest of sexual assault under parliamentary privilege. Xenophon is better understood as an opportunist rather than a populist; he is no Farage, Trump, Sanders or Le Pen.

His capacity to play the “outsider” is limited too. He has been a professional politician for over twenty years, and his recent round of recruits — people like Kris Hanna and Gary Johanson — are serial political candidates. His team gained $1.2 million in funding from the Australian Electoral Commission at the 2016 federal election.

A better explanation of his popularity and appeal lies in a much underappreciated element in Australian politics, nationalism and sub-nationalism. As the historian Benedict Anderson famously described it, nationalism encourages the creation of an “imagined community” that can enable some politicians to gain support from both the left and the right and transcend traditional divides like class.

Sub-nationalism, or regional identity, has an intriguing impact on Australian state politics, and plays out differently across the nation. The frequent call for Western Australian independence is but one example. In South Australia, sub-nationalism tends to manifest itself in at least a couple of ways: in the motif of a plucky state government playing David to the Commonwealth’s Goliath (Jay Weatherill’s shirtfront moment with Josh Frydenberg is a recent example) and in the image of South Australia standing up to the bully-boy eastern states, often over water policy.

A fascinating photo captured this second point perfectly last year, showing a suite of SA politicians calling for an independent inquiry into water “theft” by up-state irrigators. When else would the likes of Cory Bernardi, Sarah Hanson-Young and Penny Wong be rallying together? And, of course, Nick Xenophon was a prominent part of this unlikely coalition of SA voices.

Xenophon has two aims in recasting his party from the federal Nick Xenophon Team to the local SA Best: to broaden the party’s appeal beyond his own personal popularity, and to operate as a conduit for the SA sub-national feeling. He is keen to make and remake the “best interests” of South Australians without being tied to specific policies or values. He recognises the electoral appeal of the regional and local, often attracting local councillors and mayors to his team.

In retrospect, it is perhaps not especially surprising that Xenophon decided to re-enter state politics. Xenophon the federal senator was a small fish in a big pond. At the 2016 federal election, despite NXT’s gaining a strong 21.3 per cent share of the SA vote, he was unable to create a national “centrist” movement. The party received just 1.8 per cent nationally, with less than 0.5 per cent in Victoria, Queensland and New South Wales, and no presence elsewhere.

Xenophon can also draw support from some of the distinctiveness of the state’s political culture. South Australia has often fostered new political parties, including Family First, the Australian Democrats and Bernardi’s Australian Conservatives. In fact, there are clear parallels between SA Best and the Democrats: both are/were a “new” political party led by an already well-known and charismatic leader seeking to hold the majors to account. While the Democrats won 16.5 per cent of the vote at the 1997 SA election, they never translated into a dominant third force at the state level. Herein lies one difference between Xenophon’s popularity and the heyday of the Democrats: the link between power and responsibility.

The Democrats, especially during the furore over the introduction of the GST, were caught between their watchdog role and the consequences of being aligned with an unpopular government policy. The dilemma ultimately proved electorally fatal. To date, Xenophon has secured power and influence without facing any backlash associated with sharing the responsibility of office or aligning with divisive policies.

Xenophon’s popularity is also amplified by the distinct ecology of SA political parties. First, the Nationals have never had the same appeal (in terms of vote share) in South Australia as elsewhere, despite having a minister in Mike Rann’s Labor government in the 2000s. The Greens are less prominent in South Australia. And the merger of the Australian Conservatives and Family First does not appear to have bolstered their electoral prospects. Others have made little impact, either, including the vaunted Palmer United Party at the 2014 state election. Xenophon is not only appealing to disaffected major-party supporters; he is also aided by the lack of other substantial minor challengers.

There’s one other structural feature of South Australian politics that Xenophon has managed to capitalise on. Since 2002, the SA Liberals have been beset by divisions, leadership squabbles and policy inertia. Steven Marshall’s personal popularity is generally low. As Ben Raue notes in the Tally Room, while the NXT vote at the 2016 federal election came from all parties, the party disproportionately collected votes in “safe” Liberal seats. It is no coincidence that the Xenophon team includes a number of former Liberals. While rhetorically pitching against both the majors, Xenophon is seeking to make the electoral breakthrough the Liberals have been unable to achieve since 1997. •