Karl Marx himself said that history repeats itself, first as tragedy, then as farce. Supporters of Jeremy Corbyn, one of Marx's most foremost admirers, will doubtless see a ring of truth in that famous aphorism.
As you'll have read, Corbyn faces allegations of handing information to Communist spies in the 1980s. To the Labour leader's adherents, the allegations, based on documents published by The Sun, are farcical and tragic in equal measure - farcical because they have no basis in fact, tragic because they threaten to block Corbyn's route to Downing Street.
Despite Corbyn's vehement denials of any wrongdoing, the claims continue to gather pace, with suggests that they could prompt a Parliamentary investigation. It's all so uncannily similar to events nearly a century ago, when the first-ever Labour government was derailed by the Daily Mail.
Just four days before the general election in 1924, the Mail published a letter which was allegedly written by Grigory Zinoviev, second-in-command to Soviet leader Vladimir Lenin.
The headline read "Civil War Plot by Socialists' Masters: Moscow Orders To Our Reds; Great Plot Disclosed."
The letter was addressed to the British Communists with advice about how to prepare for a revolution, asking them to use "sympathetic forces" in Ramsay MacDonald's Labour Party in order to support an Anglo-Soviet treaty.
The political climate was very different when that letter was published. The Bolsheviks had won power in Russia only seven years earlier; their coup, and victory in the bloody civil war that followed, had spread terror around the world and prompted fears of trotskyist uprisings in other countries. Britain's Labour party had been founded only 24 years earlier and its inaugural government, a minority administration at that, was only nine months old. The party was still a new - and, to many people, frightening - political force.
Finally the concept of an Anglo-Soviet treaty carried genuine weight. Despite the horrors of the First World War Britain remained a great power; its endorsement would have been a major boon to the incipient Soviet state. The 'Zinoviev letter' caused palpitations far beyond the English channel.
It is now claimed that the letter was most likely a forgery, created by the intelligence agencies and sent to the Conservative Party. Desmond Morton, an MI6 agent and friend of Churchill, has been painted by some experts as the guilty party.
As the 'scandal' grew, Ramsay MacDonald said he “felt like a man sewn in a sack and thrown into the sea", a repudiation every bit as emphatic as Corbyn's own, Nonetheless the letter was viewed, at the time at least, as having a major impact on the Tories' return into power in the subsequent election. Accusations that Labour was a communist satellite, its leaders nothing more than useful idiots for the Kremlin's new figurehead Joseph Stalin, helped bring the downfall of MacDonald, whose working-class background made him an obvious target for the affluent chattering classes.
Unlike MacDonald, Corbyn has yet to be given the keys to Downing Street. He waits at the gates of power, rather than standing grinning from the other side. Nonetheless his galvanising effect on the British public, the strides he has made in such a short time, make him arguably Britain's most significant left-winger since those grainy days of the 1920s.
No matter how often Corbyn denies the spy claims, he can't stop his opponents countering that there's no smoke without fire. If a general election is convened in the next few months (and given the mephitic air of crisis which shrouds Theresa May, it can't be ruled out) the Sun's claims could be equally damaging.
May herself has certainly made political capital from the claims against Corbyn, demanding the Labour leader be "open and transparent". Meanwhile the right-wing press follows suit, asking Corbyn to open up. It's the political equivalent of the 'when did you stop beating your wife' question; a cynically loaded query which implies guilt, however Corbyn chooses to counter it.
Having threatened legal action against Tory MP Ben Bradley, who suggested he had sold intel to communist spies, Corbyn has now hinted at a clampdown on the free press. Watching him make this thinly veiled threat, one couldn't help but feel he'd fallen into the trap - turning all the speculation and innuendo into a very real piece of evidence for his enemies to gorge on.
Despite all the claims and counter-claims, despite the criticism he has received for his "change is coming" comment about the press, Corbyn continues to ride high. May's Brexit calamities continue to overshadow his own difficulties.
But surely his supporters must be getting worried, with history's shadow growing ever longer. Academic Robert Rhodes James said the Zinoviev letter gave Labour “a magnificent excuse for failure and defeat," and, if Corbyn does lose an election in the next few months, future generations of historians will no doubt claim it was the Sun wot lost it for him.