Case in point: the release this week of the Palace letters relating to Australia's one great, constitutional crisis - the sacking of Gough Whitlam in 1975 - has seen otherwise sensible individuals seeking coded language in the correspondence.

All in service of the theory that a cabal of powerful vested interests removed Whitlam from office because he threatened to upset the existing power structures. It couldn't just be Kerr acting alone: an act of such importance had to have something more significant behind it.

Instead of seeing the denials and warnings from the Palace as genuine - reflecting an understandable desire to keep the Queen out of it and for the matter to be resolved in Australia - they are seen as evidence to the contrary. The Queen's secretary telling Kerr not to use the reserve powers for political reasons is deemed a wink and nod to do just that.

If there is one hallmark of a conspiracy theory, it's when everything is evidence of guilt. Absence of evidence is treated the same as evidence. Denial is seen as a confession.

At their core, most conspiracy theories reflect something the believer either desperately wishes were true, or refuses to believe isn't true.

This hints at one reason for the persistence of the conspiracy theory. While there is no doubt that, for good or ill, many of Whitlam's reforms have endured, ultimately those who mourn his sacking lost the main policy battles in the decades after the dismissal.

Those clinging to Whitlam dismissal conspiracies can't reconcile their vision of 'Whitlam the great reformer, saviour of Australia' with the reality that Whitlam was soundly rejected by the electorate after the dismissal. Twice.

It should be instructive that the generation of Labor politicians who followed Whitlam, including those who led the longest Labor government in our history, clearly learnt far more from Whitlam's economic failure than his supposed successes.

Whitlam offered a different vision of Australia from that which came before, but it ultimately was not the direction Australia chose to take.

Yet, the Venn diagram of those who believe in Whitlam conspiracies, and those who regularly denounce 'neo-liberalism' as the cause of all the world's ills, is almost a single circle.

In their more sober moments, one imagines it's hard for Whitlam's defenders to deny his flaws, or the appalling bungles and genuine scandals that repeatedly engulfed his government. Or the ongoing economic malaise that began on his watch.

This offers an interesting parallel to Donald Trump and Hillary Clinton.

Of course, it is impossible to mention conspiracy theories without mentioning Trump. From the Obama 'birther' controversy, through to the Steel dossier and the spectre of Russian interference in the 2016 election, Trump is both the author and subject of some of the biggest political conspiracy theories in the last decade.

That it is increasingly impossible for US Republicans to support Trump without having to resort to conspiracy theories is evidence of a significant problem within the US political right.

Yet an equally big problem exists on the left. It was amazing to see the vigour with which politicians with decades of experience pursued the somewhat farcical idea that the only reason Trump won was that his campaign was basically a front for Russian interests.

That a politician like Hillary Clinton, with a track record of policy failures under a cloud of perceived dubious dealings - whose best argument for being made president was that it was her turn, and who ran an awful campaign - could be defeated should need no conspiracy theories to explain.

That the best candidates the Democratic party could muster were previously-defeated Clinton (who comedian Dave Chappelle compared to being asked to vote for Darth Vader) and a septuagenarian socialist from Vermont who wasn't even in the party, should have been clear evidence of an internal problem.

Yet her supporters, even as they admitted Clinton's faults, simply couldn't believe that the people would reject their vision in favour of the boorish Trump.

If there are two things conspiracy theorists and visionaries have in common, they are absolute confidence in their reality, and complete bafflement that others don't just 'get it'.

One wonders what conspiracy theories will emerge if the same thing happens again to current Democratic contender Joe Biden in November?

The US parallels are important for another reason. The political upheaval in the US at the moment, though triggered by different things, has a lot in common with the period before and after the dismissal in Australia.

Democrats and Republicans in the US have both been explicit in rejecting political norms and conventions. Obama's bold declaration he would ignore the legislature to pass his climate change initiatives. His use of executive agencies for political ends. The cynical games around filibusters on both sides. The inability to pass a budget. The repeated governmental shutdowns.

The refusal of the Republican-controlled Senate to even entertain Obama's judicial appointments. Trump's battles with ... well, everyone.

That both sides of politics in Australia consciously walked back from such a similar precipice after the dismissal is very important. It is easy to see how a similar breaking of political norms and conventions in the 1970s could have undermined the integrity of Australian political institutions in just the same way as has happened in the US.

In many respects, the dismissal actually reflects the efficacy of the checks and balances in the Australian system; and while it represents an extreme we don't want to revisit, it's evidence the system is fundamentally sound. By contrast, the misuse or ignoring of the checks and balances in the US system indicates a system in danger of potential collapse.

It's an important distinction. After all, Australia's political crisis ended with an election, not a civil war.