John McDonnell seems incredibly naive for a man who has spent nearly 30 years in elective politics. Seriously naive

Given this history of a party created and motivated by the highest ideals, founded and motivated by the self-sacrifice of generation after generation of its members and supporters, party members have looked on aghast, in disgust and anger at the self-interested, self-serving political faction fighting among ministers and MPs over the last week. Ambition and naked self-interest have taken over from any sense of political purpose.

As James Buchanan has been pointing out over those years this is simply what happens in a system that grants such powers to politicians.

It isn't that this year's or this decade's crop of politicians are any more venal than those of any other time and place. It's simply that the limits and checks on them have been reduced so that the innate venality is able to express itself.

For all economic actors are self-interested, it the limits that we place upon its expression which re important. In market systems we do it by competition. In politics it appears that we don't.

Let's put it another way. Would Mr. McDonnell be so aghast at a group of children gorging themselves sick if they'd got the keys to the sweet shop?  Naive to think that politicians won't do the same.

The solution is simple, simply have fewer politicians with fewer powers so that there's less of ours that they have access to.