Major constitutional reform is no different. That is certainly the case with Indigenous recognition now and was the case with the republic referendum in 1999. That is the context for Prime Minister Malcolm Turnbull's response to the Uluru declaration by Indigenous leaders. He was speaking at a function to commemorate the 50th anniversary of the successful 1967 referendum.

He developed themes he had addressed before, falling back on his experience as the leader of the defeated republican movement in 1999. In fact, he sees himself as an expert on the difficulties of constitutional reform.

His message was: "No political deal, no cross-party compromise, no leader's handshake can deliver constitutional change. To do that, a constitutionally conservative nation must be persuaded that the proposed amendments respect the fundamental values of the constitution and will deliver precise changes that are clearly understood to be to the benefit of all Australians."

That cautionary message gives away too much to the opponents of various constitutional reforms. The 1967 changes were directly to the benefit of Indigenous Australians and only indirectly to the benefit of all Australians. Yet the referendum passed easily because most Australians recognised it was the right thing to do.

In 1999, there was no political deal or cross-party compromise. Rather, the parties were divided and prime minister John Howard and many of his cabinet did not support the referendum. So don't read too much into the result.

Turnbull's response developed his recipe of what is needed for change to be brought about in a constitutionally conservative nation. Among advocates, there must be "resolute solidarity". That is undoubtedly true in any major political conflict.

But, furthermore, he argues that, in the absence of resolute solidarity, there must be "minimal or at least tepid opposition". He goes too far. That situation will be the case only when relatively trivial or uncontroversial matters are concerned. As a guide to major constitutional change, it is a recipe for disaster, offering unnecessary encouragement to opponents of change.

In Turnbull's defence, a case can be made that he is being realistic and rightly cautious. The evidence lies in the well-known statistics he falls back on. There have been 44 referendums and on only eight occasions has the yes case succeeded.

But a stronger case can be made that he is being excessively cautious. He is throwing in the towel before the fight has begun in earnest.

This sort of approach is disastrous when applied to Indigenous constitutional reform as well as to same-sex marriage and an Australian republic. There is not and never will be anything minimal or tepid about opposition to these reforms. That does not mean they are not good ideas whose time has come. If they are supported by a clear majority of the community, they should be advocated and fought for by its leaders.

On same-sex marriage reform, one can see in Turnbull's recent speech why he initially preferred a parliamentary vote to a plebiscite, which is by definition not a constitutional mechanism but which bears many of the characteristics of constitutional reform by referendum.

In later agreeing to a plebiscite as the way forward, he put the legalisation of same-sex marriage at risk from the very balance of forces that he fears. In a plebiscite campaign, there would be no resolute solidarity on the yes side among political leaders because there is obvious division within the governing Liberal and National parties. Some cabinet ministers strenuously oppose the idea. As a consequence, the opposition on the no side would be neither minimal nor tepid. The political atmosphere would be extremely hot.

When applied to politics and public policy more generally, Turnbull's approach emphasises passionate intensity rather than mere numbers. One vote one value, with two-thirds in favour of a change and one-third opposed, is not enough for success if the one-third campaigns against proposals with energy and firepower. It is a recipe for the status quo rather than reform.

Does Turnbull have a distinctively cautious approach to political change or is he representative of the modern political class?

It's tempting to do as he himself does – "As I know better than most, changing the constitution is not easy" – and to look at how he was shaped by his experience. That experience, with the republic in 1999 and climate change in 2009, when he lost the Liberal leadership, was rocky. It would be understandable if those defeats scarred him forever.

Any inclination to take the lead on constitutional and political reform may also have been knocked out of him by his battles with his own Liberal right wing and with right-wingers in the Nationals. Perhaps 18 years of such infighting, including defeats for his deeply held views, made him extremely wary.

This lesson, according to Turnbull, has immediate implications for the future of Indigenous political and constitutional reform. The Prime Minister will be guided by his own experience of past defeats.

But the lesson may be also a broader insight into his view of his fellow Australians if he believes our conservatism is not restricted to constitutional matters only but extends to life and politics in general.

John Warhurst is an emeritus professor of political science at the Australian National University. john.warhurst@anu.edu.au