Politics is about defining yourself and your opponent before they do it to you. At the moment there is a new fight on by the hard-left to define centre-ground politics - particularly progressive centre-ground politics in the Labour party - as enablers of - or even the same as - the torch-waving racists we saw in America this weekend.
If you think I am exaggerating, then just look at Laurie Penny's tweet where she literally said that 'These Nazi thugs are exactly the people whose 'right to be heard' and 'legitimate concerns' centrists have been defending for years.'
But this is not a one-off in the heat of the moment of the shock at Charlottesville. This is a concerted drive that has been underway since the election to try and discredit the centre-ground of British politics and those who advocate it within the Labour party.
This is nothing new and progressives have to acknowledge we have often been slow to play the game, partly because it is so ridiculous. But we have been guilty of letting the 'principles vs power' argument slide, because, yes, we do want to win elections as that is the way you make change happen and if the price we have to pay to get the Labour party to believe 'winning matters' is to be called unprincipled, we have regarded that as a price worth paying. But no more.
What does it mean to be on the centre-ground? I would define it as being in touch with the British public, ensuring that Labour politics delivers on their priorities and answers - with centre-left solutions - the questions they ask at election time. Hard-left politics, nor the soggy soft-left Ed Milibandism that went before it, will not do that - let us not forget that for all our gains we fell well short of winning the last general election.
So that means we say whatever the public wants to hear? No, but we do need to be engaged in the same conversation. When we are, we should seek to lead it, not follow it.
I agreed with Owen Jones when he criticised Miliband's rhetoric on immigration, but I do not agree that it means we should stay silent on the subject. In fact, the reverse. My problem was Corbyn's predecessor offering things he knew he could not deliver to bring down immigration figures and then slapped a pandering slogan on a mug.
Penny is wrong to argue that those of us she calls centrists, who know there are legitimate concerns about immigration and think if you sort them out it is the best way to help cohesion and reduce racism, are the what gives an open door to the populist- and racist-right. Pressures on public services, wage pressures and the impacts of changing communities can all be managed, supported and put right through politics. If we play into some rightwing argument that we are too 'politically correct' to talk about immigration, it is that what leaves the space open for the far right.
The challenge is what you say: things you could actually do and might deal with the legitimate problems, not feed hysteria or offer transitional demands. It cannot be vacuous slogans about 'British jobs for British workers'. It has to be making the case for our values and competence. With both we can successful prosecute the argument we know to be true: that diversity strengthens not weakens Britain.
But Penny's tweet, and the similar ad hominem attacked on centreground politics, is not about specifics. It is a general smear job that modernisers in the Labour party have continually faced through our more than 100-year history. 'Centrist' has simply become a polite way of saying 'red Tory': it sounds more academic, but simply aims to discredit. It carries a suggestion that somehow we are the outsiders in our own party, we are the ones not part of the Labour mainstream, not in touch with the worker in the street, simple technocratic and ideology- free. It is nonsense.
It is the politics of 'if you like x then you must like y'. So, if you vaguely think immigration has the occasional opportunity costs - lower wages or pressured public services on top of austerity, that fast changes in communities can cause tension - and that they should be dealt with and resolved, that the competence of our boarder force agencies could be improved then you are the same as the racists in Charlottesville.
I do not need to point out that the hypocrisy of this rhetorical device is of course exposed when the shoe is on the other foot. To suggest that having been supporters of the Chavez politics in Venezuela means that one should now speak out on the current brutal oppression of human rights is met with howls of outrage and screams of unfairness.
But what does need pointing out is there are many on the left that, like me, believe our diversity is not benign, but our strength; that a multi-racial society makes us stronger not weaker. They are right. But the view of improvement inherent in those believes should also acknowledge that diversity and multi-racial societies are 'change'. And they change can be - for legitimate or illegitimate reasons - resisted. To ignore this - as Penny's tweet inherently suggests - is the licence the populist-right yearn. It is the shutting down of debate, not seeking to engage in the legitimate end of the debate, that should be resisted.
What this whole back and forth exposes is that sadly it is a lot easier to define what you are against than what you are for in politics. It's easy to stand up and shout 'I don't like bad things'. It is much harder to look at the policy challenges of the future and say what we are for. What do we do about increased automation, an ageing population, the so-called gig economy and greater movements of people than ever before.
So let us move on from the recriminations, the random ideology tests and focus on the ideas that can ensure we can win again. When there is a real rightwing to attack in politics these days, let us not use the label on our own side. Bunching together the centre-ground and 'the right' to discredit politics that is in touch with the public is precisely the sort of strategy that will have the real right-wingers rubbing their hands with glee - from their offices in government.
Richard Angell is director of Progress