In the hit biopic Rocket Man, the ambitious young Reginald Dwight is counselled to hide his working-class roots if he wants to make it in “showbiz”:

You gotta kill the person you were born to be in order to become the person you want to be.

Arriving in Canberra in 2013, Jacqui Lambie carried just that kind of baggage – the burden of tough starts, frequent setbacks, of being a fish out of water. The former soldier is now back in the Senate for a second stint.

Her parliamentary reprise was not just something of a surprise, it lent the May 18 federal election a sense of restorative justice after her admittedly gaffe-prone first term was cut short in 2017 by a Section 44 citizenship hitch.

Read more: Lambie's vote key if government wants to have medevac repealed

She’d arrived in 2013 as a total unknown under Clive Palmer’s eponymous PUP. Impulsive, frequently angry and clearly ill-prepared, Lambie soon cut ties with the irascible mining magnate, leaving him muttering about her ingratitude and a breach of promise.

Yet in 2019, when the eccentric millionaire ploughed upwards of A$60 million into a gaudy, winless nationwide campaign, Lambie triumphed on a shoestring, boosted by Tasmanians to fill the last available Senate spot.

But there was no Elton John-style artifice involved. Forming the Jacqui Lambie Network, she would defiantly trumpet her own name and working-class roots, parading herself as the real deal, pure battler, core-Apple Isle.

It was an exercise characterised by a brutal frankness about her past. Disarmingly so.

“I was a bloody wrecking ball,” she recently told Nine Newspapers, about why she was so controversial and had flamed out in her first period in Canberra.

I just had no idea what idea what I was doing. I’d come from ten years, basically between the bed, the couch and a couple of years in the psych ward.

Now she’s back. Better, stronger and wiser for the journey.

Already, the proudly rough-edged advocate for the battler state has had a significant impact while signalling to Prime Minister Scott Morrison that her vote for future government bills will carry a price.

How much? A fortnight ago, it was A$230 million to be forgiven for the state’s social housing debt.

The concession followed Lambie’s swift post-election support for the Morrison government’s signature A$158 billion election pledge of income tax cuts for low, middle and high-income earners.

The housing debt waiver was a solid victory for the frail Tasmanian economy. It was reminiscent of the fiercely parochial Brian Harradine – a conservative Catholic independent who used his pivotal vote through the Howard years to get special deals for the smallest state.

Read more: View from The Hill: Jacqui Lambie plays the Harradine game

But Lambie’s response in the moment of victory betrayed her continuing lack of political polish.

Rather than hammer home the full weight of her achievement, she remarked that she should have asked for more, driven a harder bargain. Is this a harbinger of her approach in future fights? Probably.

What is clear is that the government’s concession, and the intent in her response, together underscore the importance of Lambie’s so-called swing vote.

With 35 senators and Cory Bernardi more or less in the bag also, Team Morrison needs a further three to reach the required majority of 39 votes in the Senate – assuming Labor and the Greens are offside.

That is, three out of the five crossbench votes comprising either the two Pauline Hanson votes plus Lambie, or the two Centre Alliance votes plus Lambie. A number of crucial bills loom.

Eager to scrape together a third-term agenda from the parched policy landscape of its unexpected victory, the Coalition is reheating ideas proposed and defeated in previous terms.

Two of them are the Ensuring Integrity Bill, which seeks to impose harsh new restrictions on unions and give the government unprecedented executive power to deregister them, and the expansion of drug testing for welfare recipients.

Lambie’s support is likely to be pivotal – depending on what the other two micro-parties do.

Another issue is the proposal to expand the cashless welfare card to reduce the incidence of welfare being spent on non-necessities.

All are controversial.

On drug testing for Newstart and Youth Allowance recipients, Lambie is playing hardball.

After initially signalling some sympathy for the plan – having seen her own son descend into ice addiction – she has since made it clear she will not support the measure unless, first, politicians agree to random drug and alcohol testing, and second, there are adequate rehabilitation facilities on the ground.

Ministers have raised no objections to being drug-tested, but rolling out enough beds for an estimated half-a-million Australians with drug-dependency issues (many of whom would not be on welfare it must be noted) is no small thing, especially as Lambie has said she wants the beds in place before she supports the testing.

Lambie’s abrasive style is such that predicting her attitude to legislation is not straightforward. This is because it is a mixture of working-class battler politics (not unlike traditional Labor values), tinged with a resentful outsider populism that tends to be more right-leaning.

Overlaid on that is Lambie’s adoption of Harradine’s successful Tasmania-first model.

Her emergence as a swing vote in the Senate puts her in a direct contest with Pauline Hanson, who already owns the populist right.

Either woman can potentially hold the whip hand on government legislation depending on the issue, but Lambie has more room to move.

For the government, that means treading carefully, keeping the lines of communication open, copping the odd spray, and hoping for no dramatic changes of opinion. This is never easy with Hanson, and even less predictable with Lambie.

Politics is often derided as show business for ugly people. Lambie seems intent on making it real business for real people – but with a touch of show business for good measure.

Mark Kenny does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.