The Overton Window is a concept beloved particularly by the Left. It's a theory about the range of political ideas that the public will accept, and the reason the Left has been particularly interested in this window in recent years is that there is a belief you can move it in a certain direction so that previously radical and frightening ideas become quite normal.
Jeremy Corbyn's supporters certainly believe that their party has succeeded in moving the Overton Window over the past few years, and that the old political adages about the public not wanting an overly left-wing party no longer apply. But within the party itself, there has also been a rather interesting movement of windows.
Over the past decade or so, the trade unions have often been portrayed as the left-wing weight holding the Labour Party down. Ed Miliband won his leadership contest thanks to the unions, and this was largely seen as a negative. He then introduced reforms which were designed to loosen the power of those trade unions over leadership elections in the future.
Yesterday some Labour delegates shouted 'shame on the unions' after a vote on the conference floor carried as a result of trade union, rather than membership, votes. The unions have opposed rule changes which would force mandatory reselection, with the NEC only proposing to make it easier for local parties to deselect sitting MPs.
The ‘traditionalist’ Labour right (the moderates who abhor all talk of a new centre party and are determined to stay and fight) say this is just a return to the way things always used to be in Labour though the decades of Attlee, Wilson and Kinnock. Unions as the moderate anchor stopping wayward left wing local party members dragging the movement away from the concerns of working people.
But a glance at the leaders of today’s Labour affiliated trade unions show they are rather a long way from the centre left position of moderation which the ‘stay and fight’ brigade are determined to restore in their party. It is unlikely that many would see themselves as a latter day Ernest Bevin, the ex-general secretary of the Transport and General Workers' Union, who relished taking on the left wing of Labour when he was brought into Clement Attlee’s cabinet. In fact, the balance is undoubtedly to the left of the gang who delivered Ed Miliband the leadership in 2010.
And yet, in order to avoid the horror of full open selections, the moderates have been fervently organising for a deal that will give these bosses an effective veto on any future leadership candidate they don’t like. Similarly, by lowering from 50 per cent to 33 per cent the threshold to trigger a full open selection contest in each constituency, it becomes at a stroke, markedly easier to kick out MPs who don’t dance to Len McCluskey’s tune. No wonder he is gloating about how easy the new rules will be to rout the moderates.
That is quite some shift in the moderates' Overton window. They’ve gone from vowing never again to allow a soft left Ed Miliband type hand Labour’s chances of electoral success to the unions, to campaigning for exactly that.