Some people want to revive centrism. Tony Blair wants to "build a new policy agenda for the centre ground". And the Lib Dems' victory in Richmond Park is being seen as a warning to the Tories that it must "keep the votes of the middle ground."

This poses the question: does the idea of political centre ground even make sense? It does, if you think of political opinion being distributed like a bell curve with a few extremists at either end and lots of moderates in the middle. But this doesn't seem to apply today, and not just because political opinion has always been multi-dimensional. What we have now is a split between Leavers and Remainers, and the ideas correlated with those positions such as openness versus authoritarianism. Where does the "centre ground" fit into this?

My question is reinforced by the fact that centrists have for a long time defined themselves by what they are not. For years, the Lib Dems biggest selling point was that they weren't Labour or Tories, and so garnered the protest vote (Oh, such happy days!) This failure to make a positive case seems to have continued. As Ellie Mae O'Hagan tweeted:

I think centrism - whatever it is - could flourish again. But it needs to make a case for existence. And it... isn't.

So, what would such a case look like? The answer, I suspect, lies in a recent speech (pdf) by Mark Carney. (The Bank of England seems to be doing a better job than the main opposition parties). He points out that the gains from trade and technology have been "uneven":

While trade makes countries better off, it does not raise all boats; in the clinical words of the economist, trade is not Pareto optimal...For free trade to benefit all requires some redistribution.

This, I think, is the essence of centrism. It accepts that globalization and free markets (within limits) bring potential benefits, but that these benefits must be spread more evenly via the tax and welfare system.

This stands in contrast to nativism and some forms of leftism which oppose globalization and favour market intervention. It also contrasts to libertarianism and Thatcherism which emphasize freeish markets whilst underplaying redistribution.

It's also what New Labour stood for. It saw that globalization and freeish markets brought benefits, but also that these had to be accompanied by policies such as tax credits to help the low-paid*.

And it's also conventional economics: markets are good(ish) ways of allocating resources, but not so good at distributing incomes.

This poses the question: what's wrong with such a vision? Phil says it's too abstractly technocratic to speak to voters:

The lived reality of voters are erased by the cult of numbers, or replacing the feeling and perception of economic relief by indices measuring GDP, inflation and wage growth. Interest becomes more and more narrowly refined into a bland national interest, expressed in increasing and decreasing metrics assumed to be in congruence with the good life.

I have a slightly different beef. It's that this form of centrism offers too etiolated a vision of equality. Inequality isn't simply a matter of pay packets but of power too. Centrism fails to tackle the latter. This is a big failing not least because policies to increase productivity might require greater equality of power in the workplace - something which technocratic centrism has long ignored.

It's become a cliché that Blair has been discredited by the war in Iraq. I fear, though, that everyone draws the wrong conclusion from that episode. The war wasn't just a moral failing but an intellectual one: as Chilcot showed, it's the sort of terrible decision you get when leaders are isolated from ground truth: Fred Goodwin's takeover of ABN Amro (perhaps the worst economic decision of my lifetime) also falls into this category.

For me, therefore, a centrism which ignores inequalities of power must be inadequate.

Herein, though, lies the sadness: even this form of centrism would be a big improvement upon a lot of today's politics.

* New Labour didn't, I think, regard the minimum wage as a device for correcting market failure or for relieving poverty. Instead, it saw it as a way of preventing employers from using tax credits to drive down wages.