In August 2016 I resigned from the official marriage equality campaign after a decade as one of its leaders because its approach to the looming plebiscite was deeply flawed.

Now, I see the Yes campaign for an Indigenous Voice making exactly the same mistakes that were made seven years ago. As a supporter of the Voice I have to speak out before it’s too late.

In 2016 marriage equality advocates, including me, were told to make our message as small as possible. The case for marriage equality was to be limited to ‘fairness’.

We were no longer able to talk about stigma and discrimination to progressive audiences or the importance of marriage as an institution to conservative ones, despite these arguments having previously won strong support.

Even stricter rules applied to engaging the No case. We were not to address any of its points directly, especially about what might come after marriage equality.

We were to religiously stick to our bland, small-target, message.

Meanwhile, whole swaths of the nation were conceded to the No case before the vote even occurred, including western Sydney and regional Queensland.

After years of successful campaigning we marriage equality veterans knew what worked.

We knew that every demographic was winnable and that our opponents’ talking points could be flipped, judo-style, to our advantage.

But the communications ‘experts’ and political operatives parachuted in before the public vote, and paid for by gay millionaires with no experience of persuasion, felt they knew better.

The Voice Yes campaign is singing from exactly the same song sheet.

Its message in favour of the Voice is blandly aspirational and lacks nuance for different audiences.

In particular it has failed to reach older, socially-conservative Anglo Australians; it’s as if they have already been wiped off as unreachable.

The Yes campaign is allergic to any discussion about truth-telling and a treaty, even though the public is mature enough to talk about all these issues at once and distinguish between them.

The Yes campaign has also failed to challenge and discredit the talking points of the No case, leaving the field open to old tropes about Aboriginal special rights, power grabs, free loading and worse.

But didn’t Australians overwhelmingly vote Yes in the marriage postal survey? Wasn’t the small-target approach a winning formula?

No, it wasn’t.

The marriage equality postal survey was won years before it was held. From 2006, every poll showed majority support for marriage equality. In the five years before the postal survey support ranged between 65 and 72%.

Just as importantly, polls and focus groups showed over 50% were so strong in their support that nothing the other side threw at them would ever change their minds. Those levels of support were due to constant campaigning for a decade.

There were high points like the overseas marriages of celebrity couples, the achievement of marriage equality in New Zealand, Labor’s decision to drop its opposition to marriage equality, and the passage of same-sex marriage legislation in the ACT that allowed 37 couples to marry without the sky falling in.

But there was also incessant campaigning at a local level.

This local campaigning won’t be found in the marriage equality histories written thus far. Historians will need to look in the Border Mail, the Colac Herald, the Toowoomba Chronicle and the Burnie Advocate to find it.

But as overlooked as that long-term, grassroots campaigning may be today, it’s what won Australia over. Those who took credit for marriage equality strode a stage built by others.

The small-target approach of the Yes campaign in 2017 not only didn’t win marriage equality, it made things worse. It reduced the level of support from the highs I’ve mentioned to barely over 60% nationally.

It left LGBTIQA+ people in places like western Sydney to endure the pain of knowing up to 70% of people in their communities oppose their basic rights.

Most of all it empowered anti-LGBTIQA+ prejudice.

Like campaigners against the Voice, campaigners against marriage equality ignored the issue at hand and focussed on fearmongering.

They said marriage equality would open the door to trans people threatening women’s safety, LGBTIQA+ school inclusion programs undermining parental rights and religious freedom suffering at the hands of anti-discrimination litigants.

The failure to nip those narratives in the bud has seen them bloom into Scott Morrison’s Religious Freedom Bill which would have weakened existing discrimination protections, the cruel crusade against trans inclusion which has recycled old anti-gay stereotypes about child ‘grooming’, vicious attacks on drag story time, and most recently, the rise of LGBTIQA+ book bans.

I’m not blaming the 2017 Yes campaign for all the anti-LGBTIQA+ prejudice we have seen since.

What I’m saying is that the postal survey gave the biggest platform ever to both anti-LGBTIQA+ prejudice, and the opportunity to challenge and defeat that prejudice.

The opportunity was seized by the No campaign but squandered by the Yes campaign.

Given this experience, I fear the same thing will happen to Indigenous people.

Not only may the small-target approach doom the Voice, it may give anti-Aboriginal prejudice a new lease of life that will make it difficult to advance any Indigenous reform in the next few years.

It’s not too late to dump the small-target approach, but realistically that seems unlikely.

Political operatives in Canberra have no faith in the Australian people. Making big issues as anodyne as possible is all they know.

The last thing I want is for the Voice to fail. But if it does, there must be a reckoning about the old-style small-target approach to public votes.

In 2017, marriage equality was already solidly supported enough to mask the failure of that approach.

But a failure of the Voice would expose just how ethically and politically corrupt small-targetting is.

Hopefully, from that failure would come a new, more fulsome, more honest and much more effective approach to winning over the hearts and minds of everyday Australians.

Rodney Croome was awarded an Order of Australia and named Tasmanian of the Year for his LGBTIQA+ rights advocacy. He was the national director of Australian Marriage Equality.