For many younger people, the extraordinary events of November 11, 1975 would hold absolutely no interest. They might know who Gough Whitlam was, but John Kerr?

For a lot of those who remember that dramatic day, however, it was like no other in modern politics.The Palace letters have reignited the argument about Kerr's action in dismissing Whitlam, and what really happened behind the scenes.

The correspondence between the then governor-general and the Queen's private secretary Martin Charteris gives an intimate running insight into the building drama, and Kerr's thinking, including his desire to inundate the Palace with material amid his concern it might be too much.

Charteris assures him: "The Queen is absorbing it with interest". In his letters Charteris steers between careful formality, reassurance to a man under pressure, and some chatty commentary. These fascinating documents have provided grist for protagonists on both sides of the dismissal debate.

Kerr's defenders point to his November 11 letter reporting he hadn't informed the Queen he was about to sack Whitlam. "I was of the opinion that it was better for Her Majesty not to know in advance." Those who argue the Palace interfered highlight the correspondence before the dismissal, in which Kerr and Charteris canvass options and the constitution.

Charteris told Kerr the governor-general's reserve powers did exist, despite claims to the contrary, but "it is only at the very end when there is demonstrably no other course that they should be used." After the dismissal, a major criticism of Kerr was that he acted too early.

The Palace, which resisted the letters being made public, entered the debate after their release, saying they confirmed neither the Queen nor the Royal Household "had any part to play in Kerr's decision to dismiss Whitlam."

The letters won't close the old argument - the question is whether they'll give any new life to the debate about an Australian republic. Anthony Albanese seized the occasion to say Kerr's action "to put himself above the Australian people" reinforced "the need for us to have an Australian head of state".

By now, Australia should have been a republic for two decades. We had the chance in the 1999 referendum, and we blew it. The yes vote was defeated by several factors - including divisions among pro-republic Liberals, the cunning of then prime minister John Howard, and the conservatism of Australians when asked to change the constitution. Since then the difficulties have increased and may be insurmountable.

There are multiple reasons why change could be even harder second time round (even after the Queen's reign ends). The issue probably resonates less than in the 1990s. It would be caught up in the culture wars, which have become deeper and more destructive in recent years.

Most important, it would be near impossible to get a model that was both safe and saleable. The 1999 model was for a president appointed by a two-thirds parliamentary majority. There was no attempt to codify the president's powers, despite the governor-general's "reserve powers" being at the core of the 1975 crisis.

These days, the public would almost certainly want the president directly elected. But that would carry risks. It could lead to competitive tension between a popular president and an unpopular prime minister.

The powers of a popularly-elected president would need to be clearly spelled out (codified). As Malcolm Turnbull has written, "Nobody would seriously contemplate leaving the powers of a directly elected president in the undefined, and thus potentially uncertain, world of convention".

One compromise some suggest would be to remove the circumstances that caused the 1975 crisis by taking away the Senate's power to block supply. Good luck with that.

Many politicians and constitutional experts would be uncomfortable with a direct-elect model. Controversy over the model would translate into a divided electorate. And when it comes to referendums, division is certainty deadly.

Look at what's been happening with the attempt to put recognition of Indigenous people into the constitution. You'd think this should be relatively easy. It's anything but. Under cover of the pandemic, the government has abandoned minister Ken Wyatt's ambition for a referendum this term. But there wasn't enough agreement anyway.

The challenge of finding acceptable wording for recognition is formidable (just as devising an acceptable republican model is fraught). And a referendum for Indigenous recognition, like one for a republic, would bog down in the culture wars.

Despite the problems, the optimists would think we could achieve both changes. The pessimists would doubt either is attainable in the foreseeable future.It's an academic question admittedly, but it is worth asking ourselves which of these constitutional changes would be of more significance to our identity as a nation.

Those who'd nominate moving to a republic would start with the obvious - we should have an Australian head of state. They'd also say becoming a republic would boost Australia's image in our region, although one suspects this point is weaker than previously - we're less defined in our neighbourhood by our British ties these days. Those who'd prefer the limited political capital to be spent on Indigenous recognition would emphasise how overdue this is, and how symbolically important.

While the flow-on effects shouldn't be over-estimated - the apology didn't work miracles - recognition could help generate goodwill and co-operation needed for tangible improvements in the lives of disadvantaged Indigenous people. Recognition of First Australians would be a gesture of reconciliation as well as a statement of our values as a nation. To my mind, it is a higher priority than the republic.