In the 1930s, a maverick young journalist named Claud Cockburn resigned from the Times and, with £40 borrowed from an Oxford friend, bought a mimeograph machine (a low-cost duplicating machine that worked by forcing ink though a stencil on to paper). With it he set up the Week, a weekly newsletter available by subscription in which Cockburn printed news and gossip that came to him from his diverse group of contacts in both the British and German establishments.

From the beginning the Week printed stuff that the mainstream newspapers wouldn’t touch because of fears of running foul of the Official Secrets Act, the libel laws or the political establishment. Cockburn, having few assets and a rackety lifestyle, proceeded as if none of this applied to him. But people in the know – the third secretaries of foreign embassies, for example, or City bankers – quickly recognised the value of the Week (for the same reasons as they now read Private Eye). Nevertheless the circulation of Cockburn’s scandal sheet remained confined to this small elite circle – and its finances were correspondingly dodgy.

And then one day everything changed. In July 1933 the British government, with Ramsay MacDonald as prime minister, hosted the London Economic Conference to discuss ways of lifting the world out of the great depression. The conference was a dead loss, but the official spin put on its dismal performance was that “useful spadework” was being done.

Cockburn produced a special edition of the Week devoted to the conference, reporting what was being said sotto voce by the delegates. The only spadework being done at the event, he opined, was that of gravediggers. On the day this appeared, the prime minister, white with fury, convened a special press conference. He railed at the plotting and conspiracies that were undermining the important work of the conference and held up a copy of the Week as an example of the kind of filth he had in mind. From that moment onwards, the financial troubles of the Week were over. Suddenly, everyone wanted to become a subscriber.

What brought this to mind was the Twitter-induced disruption in the “special relationship” between Theresa May and Donald Trump, the unexpected beneficiary of which was one Jayda Fransen and her Britain First organisation. Until the other day, few had ever heard of her. But then Trump retweeted links to three anti-Muslim videos that she had posted to YouTube and – bingo! – she and her little group were world famous. Trump, after all, has 44 million followers. “GOD BLESS YOU TRUMP!” she tweeted.

As a result of Trump’s retweeting, millions of people probably think that Britain First is a power in the land

So suddenly Britain First is a big deal? Er, no. One source estimates its membership at around a thousand. Ms Fransen was arrested last month for alleged public order offences she committed at a rally in Belfast in August, where she addressed an estimated audience of 50 people. When she stood for parliament for Rochester and Strood in 2014 she received precisely 56 votes. When her colleague Paul Golding stood for mayor of London, he received 1.2% of the vote, compared to Sadiq Khan’s 44%. And Britain First seems to be a bureaucratically challenged organisation. It was deregistered by the Electoral Commission recently for failing to confirm that its registered details were correct and neglecting to pay a routine fee of £25 – which means that it cannot now put candidates on ballot papers under the name Britain First.

In the real, physical, world, therefore, Britain First looks like pretty small beer. In the realm of electoral politics it’s clearly a minority player. On Twitter, however, it has 27,200 followers – which sounds like a lot until you realise that the Women’s Institute has 33,500, the Church of England has 74,000 and the National Trust has 772,000.

And yet, as a result of Trump’s retweeting, millions of people probably think that Britain First is a power in the land. Which provides a powerful illustration of the extent to which social media now distort the public sphere. Many years ago, the political philosopher Steven Lukes said that power comes in three varieties: the capacity to force people to do what they don’t want to do; the ability to stop them doing what they want to do; and, finally, the power to shape the way they think. This little episode suggests that outfits like Twitter have acquired that third capacity – something that Trump intuitively understood from the beginning.

Claud Cockburn died in 1981 but I was lucky enough to have known him when I was an undergraduate. Once, he asked me what I was going to do after graduation. I said that I was thinking about journalism. “Well then,” he said, “remember that the key to success is to libel someone famous early in your career.” He knew about network effects before I did. Hopefully, Theresa May also now knows about them too.