Malcolm Turnbull might get to finally pull a thorn out of his side on Saturday.
South Australian Labor Premier Jay Weatherill has been a constant critic of Canberra, refusing to play ball on school and hospital funding, and the national redress scheme for sex abuse victims.
He has also fiercely pushed the coalition on electricity, with the 2016 SA blackout sparking a national debate about energy prices and security.
But after 16 years of Labor rule, the state looks set to change government.
A Liberal win - even as a minority government - won't just mean a boost for the federal coalition in its hopes to win seats in 2019, it also means a friendlier state government to help drive national reform.
But it won't be easy, for two reasons.
In the grand tradition of opposition leaders, Liberal leader Steven Marshall has been labelled uninspiring in media and political circles.
And Nick Xenophon's SA-Best party has a genuine chance to win some seats, making him king-maker in a tight contest.
Labor's Anthony Albanese says the SA poll is similar to the Batman by-election in Melbourne being held on the same day.
"In one (Batman), the Liberals aren't running at all," he told the Nine Network on Friday.
"In the other, they're not really running, which is why Nick Xenophon has emerged as an alternative opposition leader, because the South Australian Libs under Steven Marshall are so hopeless."
Mr Turnbull and Labor's Bill Shorten have been rarely seen in South Australia during the campaign.
Mr Shorten has stuck with campaigning in Batman, which he is hoping to defend from the Greens.
The prime minister has been putting out spot fires with the Nationals and making sure US President Donald Trump's steel tariffs don't cost Australian jobs.
But Mr Turnbull witnessed a strong Liberal vote in Tasmania recently, opening up the possibility of the coalition winning some lower house seats there at the next federal election.
Labor holds six of the 11 lower house seats in South Australia, and Mr Xenophon one.
A strong Liberal vote might not just remove a thorn in the prime minister's side, it could also give him hope of retaining power in 2019.
