One night a couple of weeks back I attended two separate meetings, of different organisations, both with an interest in public life: the first had about 50 people, mostly over 60, pessimistic about the next election; the second, over 100 people, mostly under 30, optimistic about their ability to make a difference.

It might not surprise you that the first was a political party local campaign launch. And here in the United States, it might not surprise you either that much the livelier group comprised supporters of marriage as it has always been understood. But it would surprise most people in Australia, where only old fogeys are supposed to reject changing the nature of marriage.

Just six weeks ago, some polls had 70 per cent support for same sex marriage. With about a week to go in Australia’s postal vote, polling by the “no” case shows that it’s fallen to about 50 per cent, with about 40 per cent opposed and 10 per cent undecided.

In Ireland, the final poll showed just 18 per cent opposed to same sex marriage; yet the “no” vote was 38 per cent (of the 62 per cent that turned out). Perhaps every one of the opponents of same sex marriage actually voted; or perhaps “no” voters don’t like fessing up, even to pollsters.

Given the starting point, just to get 40 per cent would be a moral victory for marriage; but my instinct is that shy “no” voters mean that this result could still swing either way.

Win, lose, or draw, though, starting from scratch two months ago, the campaign for marriage in my country has mobilised thousands of new activists; and created a network that could be deployed to defend Western civilisation more broadly and the Judeo-Christian ethic against all that’s been undermining it.

So far, the campaign to defend marriage in Australia has raised over $6 million from more than 20,000 separate donors, and fielded more than 5000 volunteers to door-knock and phone canvas. This is no mean feat: the equivalent here in America would be raising about $100 million from 300,000 donors with 75,000 active volunteers.

Even now, on an Australian weekend, there’s still more people that attend religious services than play organised sport, yet sport makes you normal, and religion makes you odd, if you’re ruled by the zeitgeist.

When a football star tweeted his opposition to the code’s support for same sex marriage, this church-going celebrity went from hero to zero in moments. But despite the vindictiveness of the same sex marriage campaign against anyone who breaks cover, several thousand people, mostly young, have been prepared to do just that; to do what I know from experience is hard to get anyone to do voluntarily on behalf of an established political party.

They came out for what had been taken for granted in all places and at all times until very recently and was overwhelmingly supported by the Australian parliament just five years ago; but which now attracts an instant social media storm and reputational death.

Such robust characters, once activated, are unlikely to fade away; and could continue to make their presence felt (even after marriage is no longer an issue) because they’ve had the guts to campaign for a cause they believe in.

With the leaders of both big political parties, 60 large businesses and most of the major sporting codes all coming out on the other side – and no cabinet minister, not one, in the centre-right government prepared to campaign with them – they will understandably be wondering who and what might represent them in the years ahead.

Here is the nucleus of an organisation, created almost from nothing when the postal plebiscite was announced, to rival the left-wing activist group GetUp that’s been around for a decade; and that boasts it defeated a number of conservative MPs at last year’s federal election.

The short-term beneficiary of any new group could be the embryonic Australian Conservatives, the only national political party whose leader backed marriage as it’s always been. In the medium term, these new activists are likely to mean that the long march of the left through our institutions is no longer largely unopposed.

The plebiscite on same sex marriage is one of the legacies of my prime ministership. Initially, it was a way to keep together a government that could agree on a process but not on an outcome. But in any event, a change of this magnitude, I thought, should not just be rammed through the parliament; and a vote of the whole people rather than just of easy-to-lobby MPs would give marriage its best shot.

Now, as a backbench member of parliament, freed from the need to keep a team together by minimising internal differences, my role has been to act as a standard bearer for the values that have long-inspired the conservative side of politics. And we need more standard bearers, at every level, because a majority that stays silent soon becomes a minority. If the traditional stance of the centre-right in the English speaking tradition is to endure – to be pro-market and to be socially conservative – there have to be people prepared to stand up for beliefs; because if you don’t believe, you won’t fight; and if you don’t fight, you can’t win.

In Australia’s second largest state, Victoria – the New York of Australia, if you like – the left-wing Labor government has reportedly given LGBTI support groups half a million dollars to counsel people distressed by the same sex marriage plebiscite.

In this particular state, parents must sign a special form if their children are to receive religious instruction at school – but it must be at lunch time or before or after class and it’s limited to 30 minutes a week. From next year, though, something called Safe Schools will be compulsory for all secondary students in Victorian government schools. This is a social engineering programme that managed to trick its way into the curriculum disguised as anti-bullying, where 12 year olds are made to role play being gay and are taught that there’s really no such thing as being male or female.

The Victorian government (with some senior members resisting, to their ever-lasting credit) is also on the verge of giving doctors the right to kill some patients; a moral watershed, in my view, far more dreadful than same sex marriage but which has crept up on us, at least in part because marriage has preoccupied the national debate.

Naturally, this government also thinks that climate change is the greatest threat we face and is working to remove coal-fired power stations despite risks to the industries they sustain. And in more bad news, this type of Labor government is the prototype for the next national government, if the opinion polls are right.

There is, in other words, a massive job for these newly-energised, potential conservative activists that I saw the other night. For every protest march, there must now be a solidarity one. For every assertion of identity politics, there must now be a defence of the social fabric. For every lobby on the counter-cultural left, there must now be one on the common sense right – if even the sensible centre is to hold; for the values of centre-right party MPs can no longer be assumed and often need to be buttressed.

The notion of marriage at all times and in all places except ours: the union of a man and a woman, preferably for life and usually dedicated to their children, was based on a particular understanding of the social order that urgently needs to be rediscovered regardless of how marriage is defined.

Romantic love alone can’t always sustain the life-long commitment and the shared sacrifice for the common good that’s at the heart of marriage. We will all lose, in the brave new world of same sex marriage, if commitment is watered down; and if fewer people marry, fewer couples have children, fewer relationships last, and fewer children have stable homes.

Regardless of the same sex result, freedom of religion, freedom of speech, freedom of conscience and the right of parents to choose for their children need to be reasserted because the marriage campaign has helped to illustrate just how fragile they are. None of this will happen without community pressure, electoral pressure, and that will have to be organised in the same way that opposition to same sex marriage has been organised.

Merely debating marriage has hinted at the risks facing cultural conservatives, who are the new dissidents in the world that their decency and tolerance has made possible. The Archbishop of Hobart, for example, has faced prosecution under anti-discrimination laws for a booklet outlining the orthodox Christian teaching on marriage.

The threat of protest has caused the cancellation of pro-marriage meetings and rallies. Coopers Brewery faced a consumer boycott for sponsoring a Bible Society debate on marriage. A Christian teenager was sacked for putting a pro-marriage message on her Facebook page (and naturally, the Human Rights Commission declined to defend her). A Fathers’ Day message was denied TV airtime because it was deemed “political”. A pro-marriage advertisement that cited teaching material for kids in schools was denied prime time airplay because it was deemed “adults only”.

Parents have been lied to on the presence of gender-fluidity programmes in their children’s schools. And these depredations have taken place while the same sex activists are yet-to-win!

As our most distinguished political commentator and contemporary historian, Paul Kelly, has pointed out, along with our most distinguished living former prime minister, John Howard: the idea that you can change the understanding of something as fundamental as marriage without changing anything else is an “intellectual fraud”; it’s the “joke of the year”.

Especially if unaccompanied by any wider charter of freedoms, we can expect same sex marriage in Australia to have much the same consequences as in other countries. People will take offence at the traditional teaching and the anti-discrimination laws can be relied upon to do the rest.

In Britain, the Catholic adoption agency was forced to close, Christian schools have been pressured to change what children are taught about marriage and family, and an orthodox Jewish school has reportedly had its government funding threatened.

In America, a fire chief has been removed from his position for a book defending marriage; and a florist could lose her business because of her beliefs (Barronelle Stutzman, with us tonight). People aren’t being argued into changing their minds; they’re being bullied into abandoning their convictions.

These days we nearly all have gay friends and family members who deserve our love and respect. But that doesn’t mean we have to surrender the time-honoured definition of marriage just because that’s left-wing activism’s latest demand.

It’s not discriminatory to hold that the relationship of a man and a woman, open to children, differs from the relationship of a man and a man, or a woman and a woman. No one is saying that one love is better than another (although that’s what gay activists used to say), just that not every love can claim the title of marriage.

Love might be love, as the same sex marriage campaign asserts; but marriage isn’t the only kind of love, as everyone who’s ever had a true friend or a real life should know.

The same sex marriage push is just the latest stage in the long, slow erosion of more fundamental beliefs. It’s not just the loss of Christian faith, although a more truly Christian society would be less confused and more decent (to gays too). Christian faith, after all, has inspired and reinforced Western values but it’s not strictly necessary for them. The whole point of Christian social teaching, after all, is what reason alone can discover.

Campaigns for same sex marriage and the like are a consequence of our civilizational self-doubt and the collapse of cultural self-confidence. The decline of belief has meant a reluctance to assert principles and a fear of giving offence.

We find it hard to say “no” to gays who want to marry; just as we’re finding it hard to say “no” to Muslims who want several wives. We’re reluctant to let Christian parents take their children out of sex education classes; but once the local imam gets involved, I suspect, our cultural diffidence and our double standards might start to run the other way.

Here in America, organisations like the Alliance Defending Freedom are a sign that Western civilisation still has its friends. The organisation in Australia, as yet largely informal, as yet basically ad hoc, as yet nameless, that has sprung into being to defend marriage shows that, in my country too, there remain embers of respect for our traditions.

If the current campaign means that some drive comes finally to the promotion of our best values and the maintenance of our best selves, we should ultimately be a better society – even if we lose this fight. If same sex marriage really did turn out to mean that more relationships are stronger and deeper and more lasting, all of us would be better off. In that event, Providence might have granted us all a win, even if it looks like a defeat!

In the meantime though, there are still 3 million Australians who haven’t voted and we’re fighting to get them all because, yes or no, everyone should have a say; one way or another, the result will be easier to accept the more closely it reflects the judgment of the whole people.