On this day, exactly eight years ago, the Senate passed the Marriage Amendment Bill 2004. On that Black Friday, as a result of Labor’s capitulation to Howard’s homophobic wedge politics, the overwhelming majority of senators voted to deny same-sex couples the right to marry within Australia, and to ensure that same-sex marriages entered into overseas were not recognised under domestic law. Only the Democrats and the Greens stood up for lesbian, gay, bisexual, transgender and intersex (LGBTI) Australians against this egregious attack on their human rights.

In the spring sittings of parliament, which begin tomorrow, our parliamentarians will once again vote on the question of who should be allowed to get married – this time, on one or more bills seeking to overturn Howard’s ban and extend this right to all couples, irrespective of sexual orientation or gender identity. One thing is certain, the margin of the vote will be much, much closer this time around.

So what has changed in the intervening eight years (other than the demise of the Democrats)? Well, since 2004, the policy argument has been run and won. The trifecta of reasons advanced by the ‘defenders’ of marriage – that marriage is about religion, children and tradition – have been comprehensively debunked, time and time again. With the figleaf of these so-called arguments removed, it has become apparent that those people who oppose marriage equality are simply bigots who cannot abide the thought that gay and lesbian Australians should have the same rights as them.

On the flip-side, the arguments in favour of change – that society should treat same-sex and opposite-sex relationships equally, and in doing so finally accept LGBTI Australians as full citizens – have been successful. So successful, in fact, that a large and growing proportion of the population supports ending marriage discrimination. The Galaxy poll released last Monday found that 64% of voters favour marriage equality, and just as importantly, that a majority of Green (87%), Labor (73%) and even Coalition voters (53%) support legalising same-sex marriage.

And yet, while the margin of the upcoming parliamentary vote will undoubtedly be closer than it was eight years ago, it is highly likely that the bill(s) will ultimately be defeated in both houses, and that the vote may not even be particularly close in the House of Representatives. That would obviously be a very disappointing result for the many advocates of marriage equality, both inside the major political parties and in the community more broadly.

It is also an outcome that requires some explanation – why would our federal parliamentarians reject a social reform that is both right in principle and popular in the electorate? One of the reasons is clearly the cancerous role played by the Shop, Distributive & Allied Employees’ Association (SDA) inside the ALP. Nothing seems to motivate SDA National Secretary Joe de Bruyn like ensuring LGBTI Australians remain second-class citizens, and his union certainly has plenty of obedient federal MPs who stand ready to oppose reform.

Another explanation is the exaggerated importance given to the Australian Christian Lobby, both at Parliament House and by the fourth estate. While the ACL represents only a small fraction of Australia’s Christians, for some reason the media keeps reporting, and politicians keep listening to, the incoherent blather of Jim Wallace. This disenfranchises the majority of Australian Christians who actually support marriage equality.

Other reasons for the likely failure of the push for equality include that our federal parliamentarians are both older and more religiously devout than the rest of the population. It should also be noted that the federal parliament has a long history of being achingly slow in delivering LGTBI law reform, often lagging several decades behind public opinion (Exhibit A: 37 years after the passage of the Racial Discrimination Act 1975, there is still no federal anti-discrimination legislation for sexual orientation or gender identity).

But none of these reasons is sufficient to explain why the Bandt, Jones and Hanson-Young bills will likely end in defeat. Instead, as is usually the case, the main explanation is much simpler and more obvious. Same-sex marriage will lose in 2012 because the current leaders of the Labor, Liberal and National parties have failed in their obligation to lead – only the leaders of the Greens, with the recently departed Bob Brown, and his replacement, Christine Milne, have fulfilled their responsibilities to represent all members of the Australian community, not just the opposite-sex attracted ones.

Traditionally, major social reforms in Australia have been delivered by the party in Government, usually voting as a bloc, and occasionally with bipartisan support. Even where it was not official Government policy at the time, one or more of the major party leaders would support progressive change and help it achieve majority support. However, the current leaders of the Labor, Liberal and National Parties have all actively worked against marriage equality and are major roadblocks to it being achieved at any point in the near future.

The leader of the National Party, Warren Truss, has not achieved much of note during his political career, and is certainly not renowned for strongly prosecuting public policy arguments, on pretty much anything. True to form, he has not taken a high profile during the same-sex marriage debate. However, he has repeatedly made it clear that he opposes equal marriage rights for the LGBTI community, and will be voting no on the legislation later this year.

Truss’ major ‘achievement’ on this issue might be to lead the only political party whose entire federal parliamentary delegation votes against gay and lesbian equality. That would be disappointing, after NSW state Nationals MP Trevor Khan’s vote to support same-sex marriage in the NSW upper house earlier this year, and betrays a proud history of at least a small number of National Party parliamentarians being progressive on matters of social justice. But the main betrayal is for a political party, which claims it wants to reduce male suicide in the bush, and reverse the population drift from rural areas to the major cities, to oppose one measure which might help to counteract both.

The leader of the Liberal Party, Tony Abbott, is even more homophobic than Truss. He has consistently spoken out against extending to right to get married to same-sex couples. In fact, Tony Abbott is so passionately anti-equality that, in addition to employing his own vote against the upcoming bills, he has ruled that the Coalition frontbench be denied a conscience vote. That means the only way for any Coalition figure, from the position of parliamentary secretary upwards, to vote for equality would be to resign their position, which for political animals is a very heavy price to pay. Only backbenchers are exempt, but even they may jeopardise their chance of future promotion should they vote yes.

Tony Abbott’s antipathy is clearly very personal – there is something about equal marriage which challenges either his Catholic faith or his heterosexual privilege, or quite likely both. And his crusade against same-sex marriage has continued even after his sister came out as lesbian, and despite the fact she reportedly wishes to have the right to get married herself. Contrary to the News Ltd puff pieces from earlier this year, which tried to humanise him on the basis that he maintains an ongoing relationship with his sister, I think this makes his position even more despicable. Tony Abbott is so comfortable in denying equality to LGBTI Australians that he thinks even his own sister should have less rights than himself, and that her relationship with her partner should never be recognised as  the same as his. How disgusting.

Nevertheless, the majority of my disapproval is reserved for the leader of my own political party. It is Julia Gillard who ultimately bears more responsibility than any other single figure in Australia, even John Howard, for the fact that Steve and I will still not be able to get married by the end of this year.

It is Gillard who, despite being an atheist, a so-called ‘progressive’ and even someone who originated in the left of the ALP, has espoused some of the most conservative arguments for the preservation of marriage as an exclusive and discriminatory heterosexual institution. It is Gillard who, in addition to saying she will vote against LGBTI human rights herself, also spent enormous political capital to ensure that the ALP would only have a conscience vote on this issue rather than a binding parliamentary vote (unlike the last seven years, when all Labor MPs were expected to vote in unison against marriage equality, there is no such requirement on anti-equality MPs to support change now that the party platform expressly supports marriage equality). This ‘achievement’, secured at last year’s National Conference, almost single-handedly guaranteed that any marriage equality bill in the current parliament would fail.

When you think about it, it is indeed remarkable that the federal Labor leader has been so staunchly anti-equality, especially given the majority of the community, the majority of the ALP membership, the majority of unions, and the majority of ALP parliamentarians all favour same-sex marriage. If adopting this position was done to seek the support of religious fundamentalists in the community, then it will be in vain – they will vote for the Coalition, and parties even further to the political right, come the next federal election as they always have done.

And if it was done to curry favour with religious fundamentalists inside the ALP (both inside caucus, and the head office of the SDA), then it may well have extended her stay in the lodge, but it will not prevent her being replaced whenever they consider her to be expendable. But then, trying to find an explanation for Gillard’s position on same-sex marriage is ultimately a futile gesture, because we will never truly know why until she explains it herself, and that is unlikely to occur until long after she leaves public office.

In the meantime, we must judge the Prime Minister on her actions, and in those she has clearly failed – in her duty to lead for all Australians, in her capacity to envisage a better society, and as a human being who should treat others fairly, equally and with respect. Julia Gillard is already being judged, by myself and countless others, for standing in the way of this progressive reform. She should be in no doubt that history will judge her even more harshly. This damn spot on her political record will never come out.

These three leaders have all failed lesbian, gay, bisexual, transgender and intersex Australians, and all other Australians who believe in genuine equality, irrespective of sexual orientation and gender identity. Gillard’s failure is the worst because it is the most consequential. If Truss had supported equal marriage, then it would have changed the nature of the debate, showing that conservatives could support human rights, but it may not have changed the final result. If Abbott had supported equality (or even just allowed a conscience vote), then equality may have happened but it was absolutely not guaranteed.

But if Julia Gillard had been a champion of equal marriage, if she had chosen to fight for rather than against equality, then equal marriage would probably have become a reality by the end of 2012. Instead, it appears that LGBTI couples will need to wait another eight years or more before being able to walk down the aisle. Let’s hope that, by then, the major political parties are led by people who understand what leadership means.