The headline on the Association Press wire service last week felt so familiar. Reporting the latest news in the surprisingly tight contest between Hillary Clinton and Bernie Sanders in the battle to capture the Democratic presidential nomination, it read: ‘Clinton appeals to Democratic voters torn between head and heart’.

Substitute the word ‘Clinton’ for ‘Andy Burnham’ (or Yvette Cooper or Liz Kendall) and ‘Democratic’ for ‘Labour’, and the same headline could have been used at any time during the heady days of last summer’s leadership contest, when Jeremy Corbyn’s three rivals tried in vain to stop his astonishing victory.

In the United States, where I have been spending a few months while finishing off my new book about Corbyn, it feels as if history is repeating itself, and not just with Clinton vs Sanders in the Democratic Party.

Republicans, too, are finding their nomination contest ambushed by an upstart outsider, who, despite receiving no backing from legislators or media commentators, and having had his chances repeatedly written off by the political establishment, seems to have struck a chord with grassroots activists.

The billionaire Donald Trump (who memorably suggested banning Muslims from America) and Comrade Corbyn may not have much in common on the surface, but their ability to defy expectation and capture the imagination of those who profess themselves sick and tired of politicians and politics as usual is striking in its similarity.

Of course, Corbyn and Bernie Sanders, the Vermont senator who, highly unusual for an American politician, unabashedly describes himself as a socialist, are far more simpatico. 

The surprise with which American political observers have greeted Sanders’s refusal to accept the presumption that the nomination was the experienced Clinton’s for the taking shows how little they paid attention to Corbyn’s coup on the other side of the Atlantic last summer.

So will Trump or Sanders – or even Trump and Sanders – go on to emulate Corbyn by winning their parties’ respective nominations? And can they do one better than him and actually capture the presidency?

I would answer ‘perhaps’ to the former question and ‘probably not’ to the latter. But then, if I learned one thing while writing Comrade Corbyn, it’s that, in politics, one should always expect the unexpected.

Comrade Corbyn is available now in hardback and eBook, with a limited number of signed copies!