Cory Bernardi entered a new phase of his political career by announcing this week that his nascent Australian Conservatives party was to merge with Family First.

The merger makes sense. Both parties advance a socially conservative agenda; both have origins in South Australia. And the merger is a savvy response to the changes to the Senate voting system that were introduced in 2016.

Benefits of minor parties merging

The changes to the Senate voting system abolished the group voting ticket. So, parties can no longer make the same preference deals they had in the past.

Merging, however, will provide like-minded minor parties with benefits.

First, they will be able to consolidate their human and financial resources for election campaigns and the party’s day-to-day operations.

Second, by merging into a “super” minor party, they maximise their chances of winning Senate representation: they pool their electoral support.

This sense of electoral fragmentation has been a greater problem for minor parties on the right of the political spectrum. The Greens, after decades of evolution, appear to have consolidated their role as the lightning rod for voters from the left who are unhappy with the choices provided by the major parties.

No such party, however, exists on the right, where myriad minor parties with competing agendas are clamouring for attention.

Social conservatism

The Australian Conservatives and Family First shared similar policies on a range of issues. In particular, they opposed same-sex marriage and abortion, and expressed deep suspicion about the role humans have played in climate change.

Both parties also sought to advance “traditional” family values and have been sceptical of the socially progressive policies promoted by the likes of the Greens.

But their opposition to same-sex marriage contrasts with others on the right of political spectrum – such as Liberal Democrat senator David Leyonhjelm, who supports it.

In 2016, Family First won a national primary vote in the Senate of 1.38%. Its best performance was in South Australia, where Bob Day – who is to be replaced in the Senate by Lucy Gichuhi – won a seat after polling 2.87% of the statewide primary vote. Gichuhi, however, will sit as an independent – not as an Australian Conservatives senator.

Race and immigration

Pauline Hanson’s One Nation made a remarkable return to the Senate in 2016, almost 20 years after it first emerged. Reflecting an approach common to right-populist parties in other liberal democracies, One Nation was deeply concerned about race, migration and religion.

Led by the charismatic Hanson, the party sought to advance the interests of “ordinary” Australians in a political system that it believed was over-run by professional politicians and political elites.

At the 2016 election, One Nation won a national primary vote in the Senate of 4.29%. Its best performance was in Queensland, where 9.2% of the statewide vote garnered it two Senate seats. It holds four seats in the Senate.

Libertarian

In 2013, Leyonhjelm led the Liberal Democrats to an unexpected triumph when he won the party’s first seat in the Senate. Since then, he has built a high public profile by advancing his party’s agenda, which focuses on individual liberties and freedoms.

The Liberal Democrats advance free trade, freedom of choice, and winding back the welfare state. The party supports euthanasia, the use of cannabis, and same-sex marriage.

It is also in favour of citizens having the right to own firearms as well as ending prosecutions for victimless crimes, which it describes as illegal but not threatening the rights of anyone else. These include “crimes” such as abortion, public nudity and the consumption of pornography.

However, Leyonhjelm differs from One Nation’s positions on some economic issues. For example, he supports cuts to weekend penalty rates and the privatisation of state assets – in contrast to One Nation’s opposition to both of these measures.

In 2016, the Liberal Democrats won 2.17% of the national vote in the Senate. Leyonhjelm held onto his seat after winning 3.1% of the statewide vote in New South Wales.

Liberal-National Coalition

While the minor parties mentioned above are advancing specific policy agendas, the major right-of-centre force appears to be grappling with internal divisions about the direction of its policies.

The belief that One Nation, Family First and the Liberal Democrats are chipping support off the Coalition has prompted some MPs to agitate for the party to promote more socially conservative policies. Former prime minister Tony Abbott has continued to advocate for the Liberal Party to shift to the right.

As a major right-of-centre force, however, the Liberal Party risks alienating socially progressive voters who have supported the party in the past. And the sense of a growing threat from minor parties on the right may be overstated.

As the electoral performances demonstrate, these minor parties were successful in 2016 thanks primarily to the double-dissolution election making it easier to win seats in the Senate. These parties would struggle to have as much success under the new electoral system at an ordinary half-Senate election.

Notwithstanding these elements, Prime Minister Malcolm Turnbull’s recent announcements of changes to citizenship laws suggest the Coalition leadership is responding to demands of the right from within the partyroom. Whether these will be enough to placate those seeking greater shifts to the right remains to be seen.