Four years on from Jeremy Corbyn’s unexpected triumph, there is a realistic possibility of the election of a socialist government in Britain, or at least of the election of socialists to government. It is no more than a possibility. That it exists at all is due above all to the continuing crisis of the capitalist economy and the dissatisfaction of millions of people with their circumstances and prospects. The same situation exists across much of the world, upending all the assumptions which have prevailed for forty years or more.

The greatest difficulties for the Left lie ahead: winning an election and governing thereafter. But everything that has happened since September 2015 has better fitted it for the task, on the time-honored principle that what doesn’t kill you makes you stronger.

And there has been no shortage of efforts to kill the resurgent left: a media campaign of engulfing and almost demented hostility directed at Corbyn personally, from BBC political correspondent Laura Kuenssberg’s interrogation as to whether Corbyn would “kneel before the Queen” in week one, through to the Sun’s risible “comrade Cob” smear. An attempted coup by the Parliamentary Labour Party designed to send the Leader packing, if needs be, by barring him from standing for reelection. Theresa May’s “crush the saboteurs” snap general election, called at a moment when the putative “saboteurs” looked ill-equipped to resist a crushing. And, as of 2019, the breakaway of a rump of right-wing Labour MPs to establish a new, and already divided, party in alliance with several Tory parliamentarians in a maneuver explicitly and openly designed to stop the election of a Corbyn-led Labour government; while in parallel a new group has been established in Parliament by Deputy Leader Tom Watson to pull the party back towards the right.