One of the basic tenets of liberalism and various other progressive political moralities is a faith in humanity, a form of mielorism. Well, not quite a tenet, but a kind of ill-filled out assumption, lurking somewhere in the shadows and periodically being gestured towards. It does a lot of the legwork in justifying the idea that, insofar as is possible and once they have the resources to make the best of themselves, people ought to be left to their own devices, since it is only if people are generally responsible and well-meaning that this kind of attitude makes much sense.
That 'generally' of course can cover a lot of sins: it's not that liberals believe that people never act with malice aforethought, but that it is the exception rather than the rule, a deviation from standard practice which requires explanation. For example, an explanation of some social phenomena which relies on the claim that some relatively large group of people consciously and deliberately do evil is likely to be difficult for liberals to swallow. It runs directly counter to the thought that people are basically if not good, at least well-intentioned, and that as a rule of thumb, it is only as a result of misinformation and various cognitive biases that people do evil: call it the accident theory of wrongdoing.
This leaves an obvious problem though. People clearly do do bad things, often in very large numbers. Not only that, though, but often they either carry on doing them or otherwise repeat the mistakes of their fellows. Both of these things require explanation, for, if people basically do not want to do wrong, how is it that not only do they do wrong, but carry on doing wrong? After all, 'it was an accident' is a time- and frequency-limited excuse: there comes a point where it is negligent to have not learnt from your mistakes. What liberals, and perhaps to a lesser extent other progressives, need is an error theory, some explanation which will bear the weight of repeated failures to do the right thing by fleshing out the ways in which essentially well-intentioned people can repeatedly do the wrong thing without calling into question their essential well-intentionedness.
Conservatives don't need such a theory. They think that people are basically not to be trusted, are, as Burke put it, "afraid to put men to live and trade each on his own private stock of reason; because we suspect that this stock in each man is small" (via). Natural social heirarchies, perfected by the wisdom of the ages, contain man's baser instincts, while confining women to domesticity and the role of the music which soothes, rather than enrages, the savage beast. If you think people are basically corrupt and self-serving, then you don't need an error theory for the occassions when they behave in a corrupt and self-serving way: that's how they'll always tend to behave.
I've written before about Lord Acton's Dictum - that power corrupts, and absolute power corrupts absolutely. Although the dictum can certainly be read as a quasi-liberal defence of constitutional checks and balances, I think it's probably equally well and clearly more simply understood as a conservative claim resting on basic human venality and corruptibility. It, for example, is not difficult for conervatives to understand why the attraction of ethical ideals might well fade when they stand as obstacles to the achievement of more worldly ends, because, after all, people only really want those worldly goods. A liberal reading of the dictum has to defend a theory of power not merely as providing the opportunity for corruption, but also as creating its motivation, in the form of some kind of intellectual or informational defect for which its victim is not wholly or even mostly culpable. That is significantly more difficult, although by no means impossible.
The difficulty is to strike an adequate balance between first, explanation of the processes of belief formation by which beliefs which lead to wrongs being committed, and justification of the wrongs which are committed, and second, explanation of the processes of belief formation by which beliefs which lead to wrongs being committed, and the denial that anyone ever deliberately commits wrongs. Some kind of invisible hand mechanism, which magnifies and multiplies the results of a few either poorly-thought-through or actually malevolent acts, would seem to be the kind of thing you'd want. So this, by Chris Dillow, is interesting.
The idea is that, much like various Communist regimes in Eastern Europe, New Labour is largely made up of people who have made uncomfortable compromises in situations they thought that they did not control. Rather than destroy a system they can see some positives in, and which all the alternatives to seem to be at least as bad, these people have been forced, by various non-culpable problems of the distribution of information, into a Faustian pact with a regime that in an ideal world they would disown. I have some sympathy with this story, perhaps because, as a Londoner who studied politics at university, is a member of the Labour party themselves, and has parents who were once Labour party members , it is rather personally exculpatory.
It can't be the whole story though. There's a point in the explanation where Chris declines to give details:
[b]ut by the time he became an MP, the party had changed. The party he joined was that of the underdog and civil liberties. It became the illiberal mouthpiece of plutocrats.
What is not clear is how the Labour party became the illiberal mouthpiece of plutocrats in the first place. What is the casual mechanism? Whose is the invisible hand?