History repeats itself, but always with variations on the theme.

Sixty-odd years ago, a group of mostly religious social conservatives led by a Catholic zealot divided the Labor Party and condemned it to a protracted term in opposition.

Now a bunch of mostly religious social conservatives led by a couple of Catholic zealots seem to be doing their best to make it happen again. But this time they’re doing it to the Liberal Party.

Last time the main wrecker was Bartholomew Augustine Santamaria, better known as B. A. Santamaria. This time, it’s Tony Abbott and Cory Bernardi. But the war is being fought on much of the same ground and the tactics are much the same, too.

The next battle takes place this weekend, at the state council and convention of the Liberal Party’s New South Wales division. It is ominously titled in the plural: “Party Futures”.

The forces of the hard right have already enumerated alternative futures. One option is for the currently dominant moderate faction to agree to constitutional reform being proposed by Abbott’s Warringah branch, a change that is widely seen as a means by which the right can branch-stack its way back to control, as it has done before. The other option is to watch them walk away from the Liberal Party.

“The lobbyists can have the party logo, we’ll take 80 per cent of the party.”

One of those orchestrating the Democratic Reform Movement – as those pushing for the change style themselves – is John Ruddick, who warned earlier this week that the party would split unless the convention changed the process for preselection of candidates.

“If simple democratic reform embodied in the Warringah motion is rejected or watered down, I promise there will be a historic split in the Liberal Party. The lobbyists can have the party logo, we’ll take 80 per cent of the party,” he told Guardian Australia on Monday.

On Wednesday, he repeated the threat to The Saturday Paper. Ruddick characterised the current state party hierarchy as being “like the mafia” and railed against a number of current federal members – Trent Zimmerman, Julian Leeser and Alex Hawke – on the basis of not only their ideology but also their competence.

Such incendiary comments would likely be enough to have Ruddick, who has repeatedly been a contender for the party presidency, kicked out of it. Except he is out already, having resigned in acrimonious circumstances in late 2015.

Now he serves as the conduit from party insiders to those outside, particularly the media. Thus The Saturday Paper, along with other outlets, was provided with details of the conference motions and an email addressed to party members signed by the president of Abbott’s federal electoral council, Walter Villatora, and retired major-general and hopeful candidate Jim Molan, pressing the reform case.

The essence of the motion is that the Democratic Reform Movement wants greater power over candidate selection to be vested in the party rank and file. As things stand, the political professionals on the state executive run the show.

Those professionals are moderate and see success for the party in cleaving closer to the centre of politics. They have repeatedly intervened in the selection process to rub out candidates they see as too extreme. They see this as pragmatic politics.

The hard right sees it as corruption of process. Indeed, they imply corruption more generally. No doubt there exists a happy symbiosis between those who run the party now and certain vested interests. In the email passed on by Ruddick, Villatora and Molan rail against “the current culture of rorts and the stench of commercial conflicts by lobbyists”.

They say: “There are millions of dollars at stake in preserving the domination of our party by the tiny cabal who now own it … so we can expect them to fight to the bitter end.

“The faction holds power by a constant tactic of delay, distract, dissemble, dilute, demoralise – and expel those who dare speak up about this dreadful state of affairs.”

A click on a button embedded in the email and members can hear radio shock jock Alan Jones sounding off about the “shameful, disgraceful and blatant” rorting of preselection by the state executive of the party.

There is also an app the reform movement is using to allow members to access literature and videos of Abbott and others pressing the reform case. According to Wednesday’s edition of The Sydney Morning Herald, the app was created by an outfit called Right Mobile Pty Ltd, and previously used by the Tea Party movement in the United States during their insurgency against mainstream Republicans. Apparently the Liberal hard right in NSW is technologically forward looking, even if it is socially backward looking.

They are pulling out all the stops. On Wednesday Molan defied the party ban on airing its dirty laundry in public – on pain of expulsion – by pressing the case for rank-and-file plebiscites on Jones’s radio show.

The political/religious hard right now has an option other than the Liberal Party – the party set up by Senator Cory Bernardi.

Those pushing for change argue reforms would revitalise a moribund party by giving the true believers greater say through the branches.

The moderates and their allies in the slightly less right-wing faction argue that while such “democratisation” sounds good in theory, it has not worked in other states where it has been implemented. To the extent membership has increased, they say, it has done so through the stacking of branches with members of conservative churches and ethnic groups.

They point to recent history in NSW – years in the political wilderness from the mid-1990s, when the religious right was in control, and the electoral success enjoyed under moderate leadership since 2011.

This factional manoeuvring has been going for decades, but this weekend’s meeting at Rosehill Racecourse promises to be particularly consequential, for two reasons.

The first is that the political/religious hard right now has an option other than the Liberal Party – the party set up by Senator Cory Bernardi, who split from the Liberals last year. Bernardi, a right-wing Catholic, also subsumed the right-wing Pentecostal force, Family First, into his Australian Conservatives.

Bernardi has scheduled two events in coming weeks in Sydney, the first of them to take place next week. It has reportedly already sold out 450 places. The other will take place on August 29, at Roseville Golf Club. The local Liberals branch has invited Bernardi to address members. The topic: “Is the Party Over?”

The second reason the NSW constitutional debate is particularly important is that it has become a proxy war between Prime Minister Malcolm Turnbull and Abbott. Nikki Savva, a former Howard government staffer, put it dramatically in a column in The Australian about a week ago.

Abbott was backing the push for reform “as part of a dedicated wrecking campaign against Turnbull,” she wrote.

“Senior Liberals say that not only is Abbott determined to destroy Turnbull, he wants to bring him down before his second anniversary as prime minister on September 15 so he does not serve a day longer as prime minister than Abbott did.”

Abbott was focused on three issues, according to Savva: NSW party reform, the response to Alan Finkel’s energy report, and same-sex marriage.

The modern Liberal Party, under founder Sir Robert Menzies, was overwhelmingly white, Anglo-Saxon and above all Protestant – mainline Protestant, the kind of which is not so much a faith as a class. At one point, the federal party under Menzies included just one Catholic.

Politics were much more religiously binary then. Catholics favoured Labor; Protestants favoured the Liberals.

Then Labor split. In 1955 a new party formed, the Democratic Labor Party (DLP). It was primarily concerned with the threat of communism, which it correctly saw as antithetical to religious belief. It was also very socially conservative. To the limited extent it focused on economic policy, it tended towards the position of the Liberals. The DLP was not entirely Catholic, but it was the new home for conservative Catholics. The Catholic progressives stuck with Labor.

For almost 20 years, the DLP was instrumental in keeping Labor from power. But it gradually declined, and effectively ceased to exist at the federal level by the early 1970s.

The DLP served as a conduit by which a new cohort of religious conservatives was transferred from one side of politics to the other.

As political scientist Professor John Warhurst of the Australian National University wrote in 2010: “The transfer of Catholic allegiance from Labor to the Liberals at the parliamentary level has been the most dramatic shift in Australian politics over the past 50 years.”

Not all were entirely comfortable with the new political alignment, however.

Thirty years ago, having recently abandoned his plan to become a priest and uncertain about his future, Tony Abbott wrote to B. A. Santamaria – whose socially conservative, virulently anti-communist National Civic Council (NCC)was instrumental in splitting Labor and who Abbott has acknowledged as his political hero – canvassing the prospect of getting into politics.

Abbott had come to the view that the conservative religious values they shared were not best served by simply criticising from the sidelines. The NCC’s views needed direct parliamentary influence. The question was, which party offered the better prospect?

The “roots and the origins of our culture” were in Labor, Abbott wrote. If the ALP were not “dominated” by Santamaria/NCC/Catholic right ideas, it would instead be held in “the grip of the Left and soulless pragmatists”.

On the other hand, the Liberal Party was lacking direction, divided between what Abbott called “trendies and the more or less simple-minded advocates of the free market”.

“To join either existing party involves holding one’s nose,” he wrote. “But to do nothing dooms us to extinction.”

So Abbott joined the Liberals.

In 2012, when Abbott took the leadership of the Liberal Party and political insiders began joking that Australia seemed set for its “first DLP government”, Santamaria’s biographer, Gerard Henderson, was not amused, noting that Abbott was only 16 when the DLP expired.

But there was an element of truth, and that was that the religious right had become very powerful in conservative politics. And it still is, despite the change in leadership. Nor is it just Catholic.

Survey the government. The Liberal and National parties are not populated by mainstream Protestants as in Menzies’ day. Abbott’s first ministry was about 50 per cent Catholic. Others belonged to other conservative sects.

And although Abbott is now gone from the leadership, conservative Christians still call the shots on many issues.

Why has the government stalled on same-sex marriage, despite the fact that a sizeable majority of voters and even Coalition voters support it? Because the party base and his religious party colleagues won’t wear it.

Look at those who have supported Abbott’s insurgency or defied Turnbull: Kevin Andrews, conservative Catholic; Eric Abetz, a member of the Christian Reformed Church; Michael Sukkar, who recently provided Abbott a forum to attack Turnbull, conservative Catholic; George Christensen, Antiochian Orthodox.

Even among those senior figures on whom Turnbull depends for support, we find the religious right: Finance Minister Mathias Cormann, for example, is a conservative Catholic. As is Barnaby Joyce. Treasurer Scott Morrison is a conservative evangelical. The list goes on.

Religion has split politics once before. It was a disaster for the Labor Party.

History repeats but with variations. The preoccupation with personal morality is a constant, although the Catholic right of a half-century ago could never have foreseen popular acceptance of same-sex relationships. Santamaria and the industrial “Groupers” who fought communism in the unions had never heard of climate change, but the contemporary religious right holds not dissimilar fears about global efforts to combat global warming, seeing it also as a secular “religion” and a threat to nationalism.

The tactics of seeking political power through the infiltration of existing political structures are the same. And so is the single-minded determination to win control of those structures, or else to wreck them. Santamaria’s apostle Abbott is its embodiment. And perhaps in Bernardi’s new movement, we have the next DLP, the breakaway party that ruins the political chances of its parent.