But nobody can say for sure whether the huge momentum he had at the start of the campaign will be enough to push him over the line.

His SA-BEST party has fielded candidates in 36 of the 47 Lower House seats, making him, on paper at least, a possibility to form a majority government.

But that has never been Xenophon's goal. Instead, he hopes to win the balance of power and, in his own words, "keep the bastards accountable".

It's uncharted territory, and Xenophon has come under fire for running candidates in more than half the seats yet lacking the policy and costings of a party that could form government.

The promises he's made include new laws to protect vulnerable South Australians from abuse, cutting energy prices, reducing poker machine numbers and, controversially, introducing mandatory rehabilitation for ice users.

Support for Xenophon started strong, with a December Newspoll showing 32 per cent of the state's voters would direct their first preference to SA-BEST at the election.

He looked to have found support from voters disillusioned by the 16-year Labor government but unwilling to put their faith in the Liberal alternative.

"Between Labor and the Liberals, the choice is between a government that deserves to lose, and an opposition that doesn't deserve to win," he said during a debate at the SA Press Club.

But by early March, that figure had slumped to 21 per cent, behind the Liberals on 32 per cent and Labor on 30 per cent.

More concerningly, an Advertiser-Galaxy poll published in the week leading up to the election showed the former senator might not even win his own seat, trailing incumbent Liberal MP Vincent Tarzia 51 to 49 per cent in the two-party preferred vote.

Though, as Xenophon has proven time and time again, he shouldn't be underestimated and certainly not discounted.

In 1997, he became the first independent elected to the South Australian Legislative Council in 60 years on his No Pokies ticket - a policy he backed down on earlier this year.

He became a key player in state parliament and pushed for a ban on poker machines as well as reforms to consumer rights, tax, environmental policy and politicians' entitlements.

Xenophon was re-elected in 2002, and by his 2006 campaign he had tapped into the power of publicity that would become his hallmark.

He won a seat in the Senate in 2008 and modelled himself as a champion for the state, endearing him to South Australians the way Jacqui Lambie has in Tasmania and Pauline Hanson in Queensland.

So, his re-immersion into state politics was logical - and timely.

As voters become more disillusioned with the major parties, the appeal of a character like Xenophon grows ever stronger: what you see is what you get.

But, as the election campaign has revealed, riding the wave of populism will only get you so far before attention turns to policy.

The 2018 election is an opportunity for Xenophon to reboot politics in South Australia.

Or perhaps, such a lofty goal will prove too much for the stunt master.

Australian Associated Press