Last week, a group of people marched through London calling for those they disagreed with to be “beheaded”, “massacred” and “annihilated”. A pretty clear case, you’d have thought, of incitement. After all, such talk can no longer be dismissed as empty swanking. In the past five years, we have seen British boys leaving Tipton and Wanstead and Beeston to fight and kill their fellow subjects, whether in Afghanistan, Gaza or London. When the marchers dressed as suicide bombers, and called for “a real holocaust” (with the horrible insinuation that Hitler’s genocide hadn’t been real), they were not acting out a harmless fantasy. They were encouraging murder. And, sure enough, the police did detain two people for breaching the peace – not Islamist protestors, you understand, but two counter-demonstrators who were thought likely to upset the marchers.

Now go back a couple of years, and look at two other policing decisions. When countryside demonstrators rallied in Parliament Square against the hunting ban, they were dispersed with baton charges. But when anti-capitalism activists descended on the same spot, tore up the grass and vandalised the statue of Winston Churchill, the police looked on amicably. I happened to be there, and watched open mouthed as police officers held up the traffic so that the anarchists could go about their business undisturbed.

Or consider the case of the pensioner who was charged with “racially aggravated criminal damage” after scrawling “free speech for England” on a condemned wall. Perhaps equality awareness counsellors had so drummed into local policemen their mantra that “free speech can never be used as an excuse for racism” that the two things had become blurred in the coppers’ minds, and the very fact of demanding free speech was thought to be proof of racism.

I think these decisions are crackers; others doubtless applaud them. But, right or wrong, they are plainly subjective. These days, chief constables habitually make decisions that are – to borrow Michael Howard’s distinction – political rather than operational. They decide, for example, whether or not to treat the possession of cannabis as a crime. They presume to tell Parliament what kind of anti-terrorist laws in should pass. Yet we have no say over their appointment.

The result is that senior policemen can drift away from their publics. I remember a survey carried out six years ago, which asked a number of constabularies what their priorities should be, and then asked the general public the same question. Sure enough, the police replied that they ought to be concentrating on cracking down on sexist language in the canteen, hiring more ethnic minority recruits and so on. The rest of the world thought they should concentrate on being beastly to criminals.

As things stand, there is no way to reconcile these contrasting approaches; no mechanism to make the former subject to the latter. Hence the argument in favour of placing the police under local democratic control.

In June, I and a group of newly elected Tory MPs wrote “Direct Democracy: An Agenda for a New Model party”. In it, we set out a scheme for the comprehensive decentralisation of power in Britain. Among other things, we called self-financing councils, the repatriation of power from Brussels, a local sales tax and pluralism in education and healthcare. We also called for the democratisation of the powers of Crown Prerogative – an idea that David Cameron took up on Monday.

Central to our plan was the idea of locally elected Sheriffs, who would assume the powers currently exercised by police authorities and by the Crown Prosecution Service and control their budgets. To his credit, David Cameron has embraced this idea, too.

We don’t yet know what will be in the next Tory manifesto, of course, but the idea of accountable policing could transform the fight against crime and restore honour to our electoral process. Imagine that your local Sheriff had to choose whether to spend his budget on a dedicated patrol in your village, or on more speed cameras. Imagine that he had to decide what kinds of cases to prosecute – whether to go after home-owners who had defended their property with force, for example – and that he then had to stand for re-election on the basis of his record.

Ideally, the Sheriff would also be able to set local sentencing guidelines – although not to interfere in individual cases. This may well lead to pluralism (or “unfairness”, as opponents will call it). Suppose that the Sheriff of Kent wanted shoplifters to serve a custodial sentence, while the Sheriff of Surrey didn’t. One of two things might happen. Either Kentish crooks (and crooks of Kent) would flood across the county border in such numbers that Surrey would elect a tougher Sheriff, or the ratepayers of Kent would get sick of having to fund all the requisite prison places. Sensing his electorate’s mood, the Sheriff of Kent might conclude that rehabilitation is cheaper, in the long run, than incarceration. Or he might decree that, instead of going to prison, shoplifters should be made to stand outside Bluewater with a placard around their necks saying “shoplifter”, I don’t know what would happen. That’s the whole point. It would be up to each community to settle its affairs. I’ll tell you one thing, though: people would have an incentive to vote again.

And we should be frank about something else: there will be hard cases. Perfection is not to be had in this world, and there will be inept Sheriffs, just as there are innovative and creative ones. But at least it would be up to us. We would have rediscovered that vital principle that decision-makers should be accountable to their communities.

This splendid English notion has thrived in America but withered here – rather like those varieties of grape that survived in California while the phylloxera blight wiped out their ancestral stock in the Old World. It’s time to bring Sheriffs home.

What’s that? You don’t see what any of this has to do with Europe? You don’t read The Brussels Journal just to hear Hannan ranting on about domestic British policy? Fair enough. But think about the logic of what David Cameron is doing. There is a consistent theme that links his various domestic policies, from Sheriffs, through the democratisation of the Prime Minister’s patronage powers, to the winding up of the regional assemblies and the downward transfer of their powers. In each case, he is seeking to bring decisions closer to the people they affect. Having established this principle at home, it can only be a matter of time before he extends it to the EU.