From the Greens to One Nation, the United Australia Party and the Justice Party, minor parties have become a fixture of modern Australian politics.

Queensland has the fiery populism of Pauline Hanson, Victoria elected "human headline" Derryn Hinch, and controversial conservative Cory Bernardi represents South Australia in the Senate.

And that's just the start; every state has at least one federal representative from a political party outside the Labor or Liberal-National duopoly.

This would have been shocking — perhaps even unbelievable — to someone at the ballot box in the 1950s.

But the minor party is now ubiquitous, after a chaotic rise driven by changes in electoral laws and demographics — and the clever use of preferences.

The secessionists

The door opened to minor parties in 1948 when Ben Chifley's Labor government amended the Australian Electoral Act.

Before the proportional system was introduced, the party with the biggest vote share could claim the entire state, making for a particularly homogenous Upper House.

Ben Chifley's Senate voting reform might have been his most lasting legacy. ( Getty: Popperfoto )

But Chifley's changes meant a state was more likely to have their Senate seats filled by multiple parties, depending on how much of the vote they received.

In 1955, after the split from the Australian Labor Party (ALP), the Democratic Labor Party (DLP) — then branded the Anti-Communist Labour Party — became the first minor party to crack the Senate in the post-war years.

Until the 1970s, the DLP helped itself to a share of Labor's working-class base, with its preferences helping the Coalition remain in power for 23 unbroken years.

The next political breakaway came in the mid-1970s in the form of former South Australian premier Steele Hall and his Liberal Movement.

Steele Hall's Liberal Movement was a brief defection, but set a precedent. ( Wikipedia Commons )

After losing his premiership, Mr Hall went out on his own to win a lone seat in federal parliament in 1975, to only rejoin the Liberal Party a year later.

It was a brief defection, but it set a precedent that did not go unnoticed by centrist Liberal frontbencher Don Chipp.

A few years later, in 1977, Mr Chipp founded the Australian Democrats.

The Democrats were a force for over two decades, preaching environmentalism, Indigenous rights, gender equality, multiculturalism and the value of the public sector.

When the Democrats moved in, the Senate began to play a new role in the parliamentary system, changing the "house of the living dead" into the house of review.

The grassroots

Chifley's voting reforms led to some unwieldy elections, as the number of candidates multiplied.

Voters had to number every candidate on the tablecloth-sized ballot paper, and almost one in 10 ballots were deemed invalid due to numbering errors.

In 1983, the Hawke government gave electoral law another shake-up, and the single transferable vote was joined by the group voting ticket (GVT).

This gave voters the option of placing a cross in a square above the line on the ballot. Their preferences would be automatically selected by the recipient of the single vote.

"Voting above the black line for Senate contests allowed for parties to organise preference deals in order to reach the required quota to win a seat," political scientist Zareh Ghazarian says.

"It also increased the number of senators per state from 10 to 12, which meant that the quota needed to win a seat in the Senate was reduced."

It marked a new opportunity for minor parties.

The first to emerge was the Nuclear Disarmament Party (NDP), which quickly gained traction — helped by the candidature of Midnight Oil frontman Peter Garrett.

Rock musician Peter Garrett helped raise the profile of the National Disarmament Party. ( Getty: David Corio/Michael Ochs Archives )

Concerned the NDP would diminish its own electoral performance in 1984, the ALP in NSW used the GVT system to run a "put the NDP last" campaign, denying them a spot.

In Western Australia, where Mr Garrett was not on the ballot paper, the NDP wasn't seen as much of a threat by the major parties.

It was able to win Senate representation with a smaller primary vote.

Its single-seat victory, a meagre yet unprecedented taking for a grassroots party, belonged to anti-nuclear peace activist Jo Vallentine — but it was short lived.

Anxious about a socialist takeover, Ms Vallentine took her NDP winnings and founded her Vallentine Peace Group, from which evolved the WA Greens in 1990.

It would take only a few years before the WA Greens met Bob Brown, who was known for environmental activism in Tasmania, from the Australian Greens in the Senate.

The two parties melded, and since then the Greens have won seats in parliament in every Australian state.

Bob Brown was known for his activism in Tasmania before he entered parliament. ( Getty: AFP/William West )

Politics of the right

Pauline Hanson's maiden speech to parliament, in which she called for "abolishing the policy of multiculturalism", was an incendiary introduction to minor parties of the right.

Pauline Hanson's first election to parliament is well remembered. ( Getty: Bradley Kanaris )

Senator Hanson, having been disendorsed by the Liberal Party for her comments on race and immigration, had branded her right-wing politics under the banner of One Nation.

Running on an anti-system platform, she won a single Lower House seat for the first time in 1996.

She lost that seat at the 1998 election, and unsuccessfully contested several other ballots in the years that followed. She was elected to the Senate in 2016.

The Family First Party — running on a platform opposing euthanasia, pornography and same-sex adoption — won Senate representation for the first time in 2004.

It seized on a "preference harvesting" strategy, using Labor's premeditated preferences to get across the line in Victoria despite attracting only 1.9 per cent of the primary vote.

"Family First was able to attract the preferences of other parties, as well as the major party preferences, in order to win its inaugural seat," Dr Ghazarian says.

"This was a significant result as it demonstrated to other minor parties that they too could win a seat if they organised a series of beneficial preference deals with other parties."

Former senators Bob Day (left) and David Leyonhjelm at work in the chamber in 2016. ( ABC News: Nick Haggarty )

Enter the preference whisperer

Preference deals were really thrust into the spotlight in the 2013 election, when "preference whisperer" Glenn Druery shaped the Senate using the magic of maths.

Mr Druery was the organising force behind the Minor Party Alliance, a group of two dozen fringe parties as disparate the Australian Christians Party and the Sex Party.

Through preference harvesting, Mr Druery tilted the ballot in favour of groups like the Motoring Enthusiasts Party, whose leader Ricky Muir was elected with a primary vote as low as 0.23 per cent.

The colourful 44th Parliament proved a challenge for its prime ministers, Tony Abbott and Malcolm Turnbull, who shared an appetite for electoral reform.

In the lead-up to the 2016 election, Mr Turnbull proposed that he would give preferences back to the electorate by allowing the voter to number multiple boxes above the line.

The reforms were passed after a spectacular 28-hour sitting of Parliament that saw politicians wearing pyjamas and making fart jokes.

Former minor party leader Nick Xenophon sported his Pyjamas during a mammoth parliamentary debate on Senate reform ( ABC News: Francis Keany )

Despite expectations — and partly as a result of a double dissolution — Mr Turnbull was returned with a minor party crossbench even more colourful than its predecessor.

The Government was faced with a new Senate crossbench of 20, including nine Greens senators, four One Nation senators and a plethora of other parties with three seats or less.

The minor parties of the 45th Parliament, in a seemingly constant state of formation and reformation, have made their presence well known.

As Australia heads into another election, it is nearly impossible to predict an outcome, but the spectacle of minor parties is not trivial in Canberra.

"Electoral results have shown that growing numbers of Australians are willing to support a minor party in the Senate," Dr Ghazarian says.

"Based on these results, whichever major party forms government, they will most likely have to work hard to gain the support of crossbenchers made up of minor parties to pass legislation through the Senate.

"2019 is unlikely to be different."