Simon Wren-Lewis laments the failure of the centre-left to offer a radical response to the financial crisis, the legacy of which is of course still with us. This raises a paradox - that the centre-left is weaker politically than intellectually.

What I mean is that there is, in principle, a reasonable centre-left economic programme. This would include:

- A defence of immigration, pointing out that perceived pressures on wages and public services are, largely, illusions. It's austerity to blame for these, not (for the most part) immigration.

- Redistributive taxation. Tax credits, financed by taxes on land and inheritance are both egalitarian and efficient.

- Financial sector reform. Demanding higher capital requirements for banks, for example, isn't especially radical. Nor are policies to ensure better funding of entrepreneurs, as Liam Byrne has advocated (pdf).

- Public sector reform (pdf), on the grounds that it's more necessary to increase efficiency when these cannot be so generously funded

- Policies to raise productivity. These would include infrastructure investment, better schooling especially in early years and investment in R&D.

We all have opinions on this sort of programme. But it would be a reasonable, coherent (if for me incomplete) offer. Hence the paradox - that the centre-left is weaker politically than it need be intellectually.

Why? Simon touches on the answer when he decries the centre-left's obsession with "electability" - a word that has become a whine of over-entitled narcissists.

This, though, is part of a bigger problem with the centre-left. It failed to truly mobilize radical opinion; a good gauge of this being the fact that Labour party membership more than halved between 1997 and 2010. Yes, Blair won three elections. But this owed much to useless opponents; a growing economy which bought off opposition to immigration and allowed for improved funding of public services; and to short-term spin-doctoring which people now see through.

There's long been a debate on the left about the efficacy of the parliamentary versus extra-parliamentary roads to socialism. The collapse of Blairism as political force has shown that a purely parliamentary approach is destined to fail. You can't become a lasting, successful political force if you never leave the Westminster bubble. As Phil says:

Cocooned by parliaments, cushioned by the media, and swaddled by self-importance, [the centre left] never saw the insurgency coming, and it's that lack of foresight that condemns them to the political wilderness.

It would, however, be wrong to draw a sharp dichotomy between policy - which as I've said looks attractive - and strategy. New Labour's disregard for mass popular, grassroots politics was part of a wider intellectual defect - an excessive faith in hierarchies and "elites". Gordon Brown, for example, consistently praised bank bosses as leaders and wealth creators, and invited them into government. And the emphasis upon target culture and managerialism meant that New Labour demoralized and disempowered precisely the people whom it should have empowered - frontline public sector workers.

Herein. I think, lies the reason for the weakness of the centre-left. The financial crisis was, to a large extent, a failure of top-down organizations. It therefore undermined a core belief of statist, hierarchical New Labour.

A radical response to the crisis requires that "elites" be challenged. New Labour and its epigones are unable to do this.