When, after Ukip's success in the English local elections, the Tory leadership decided it would be sensible to stop calling them loonies, I hadn't anticipated that they would go on to apply the same description to their own supporters.

Yet, according to two separate political reporters, that is what a close ally of the Prime Minister did, saying that "the [local Conservative party] associations are all mad, swivel-eyed loons".

As a political tactic, this is at the least tactless. I'll go further, and say that it is catastrophically stupid and compounds the shambles in which the party finds itself over – what else? – the EU.

As it happens, this senior Tory was trying to explain the reason for the party's vacillation about offering an in/out referendum, and then – having actually done so – still being presented by a revolt of 116 of their own MPs voting against the Queen's speech, because it hadn't mentioned one.

Even I, who would love to get us out of the EU pronto, think this is nothing but stark, staring lunacy. But since the party hierarchy needs to insist that the MPs in question aren't lunatics, and that David Cameron's leadership isn't in question (though it is), presumably the buck has to be passed to their constituency activists.

It hardly matters who said this (the co-chairman of the party, Lord Feldman of Elstree, has vociferously denied that it was him) or, to be blunt, whether anyone did. The point is that grassroots Tories think it is exactly what the party's leadership thinks of them.

On one level, that isn't very surprising. I suspect that the leadership of all parties occasionally feel a degree of exasperation with their supporters. Nick Clegg's views are not those of most Liberal Democrat activists; Ed Miliband must often feel that the unions who secured his job for him are less than helpful; Alex Salmond, one imagines, must now and then think that the stridency of the cybernats doesn't always show the cause of independence in its best light. Nigel Farage, it seems, can't go a day without being embarrassed by a supporter.

To say as much, however, is counter-productive, if not politically suicidal. All political parties are at root nothing but their supporters; to be sure, a leader's job is to lead, but there is no point in leading the way to a destination where no-one wants to follow you.

This is particularly true of the Tories. When Lord Feldman's name was bandied about (on Twitter, of course) I at first thought of Lord Feldman of Frognal who was, in the mid-1980s, chairman of the party's National Union – the umbrella group for the local associations. The other Lord Feldman, by contrast, is co-chairman of the party machine, which runs Central Office. These days, that post is where the power lies, but historically, much more of the power used to lie with constituency parties themselves.

Centralisation of this sort is not confined to the Tories, of course; it was an essential part of creating New Labour. And any party wants to dissociate itself from extreme or damaging views, whether it is Labour's Lord Ahmed or Nigel Farage weeding out the more barmy or unsavoury people attracted to Ukip.

But part of the philosophy of the Conservative party has been to advocate localism and decentralisation. Some years ago the Direct Democracy movement, which included a number of MPs who are now Cabinet ministers, set forward proposals for much more use of referendums, elections for many public posts, and a sort of devo max for every region of the country. And in, for example, health and education, the Tories are doing some of that.

Much of this impulse, however, has not found its way into policy, for two reasons. One is the tendency of all governments to decide that, after all, they would rather keep power than give it away. The other is to do with the party, its internal discipline, and Mr Cameron's belief that it needed to be repositioned. A key component was to get MPs and activists to stop banging on about Europe, the chief interest of many of them, but of not all that many voters. In fact, polls suggest it's not even the chief interest of people who vote Ukip.

Well, we can see how well that's worked out for the Prime Minister. The last few days have established licence for everyone now to bang on about the EU all the way to the next Parliament, when the referendum promise won't be worth the paper it's written on in any case, because no Parliament can bind its successors.

It's of interest to the other referendum, too, because a poll at the weekend suggests that Scots would be more likely to vote yes to independence if it looked as though the UK would vote to leave the EU.

One can't help feeling that last week's Farage farrago in Edinburgh could have been easily avoided; his opponents looked foolish for trying to paint him as some sort of racist while, apparently without irony, telling him to go back to England. But why did they even bother? Mr Farage's party is attracting no more than two Scots out of every thousand; they could practically all get into the pub at the same time as their leader.

I'm very interested in the outcome of both referendums, and very keen that the debate over both unions is properly aired. On that basis, I have to conclude that the swivel-eyed loons at the grassroots have shown a great deal more sense than the leadership of the Conservative Party.

Mr Cameron would surely be in a happier position if he had simply accepted that letting the electorate choose between the options was the right thing to do. By expending his energy trying to avoid that, he's managed to alienate almost everyone. And even when he finally tried to do the right thing, and allow people a say, he's managed to do it in such a ham-fisted fashion that he's reinforced the notion that he and his friends hold his own party's foot soldiers in contempt.

If ever there was an argument for trusting the people, and moving as many decisions as possible to the local level, it is that kind of party management. Mr Cameron doesn't just need to look at the case for devo max in Scotland, but for the rest of the UK, and for their own internal affairs. Without that, it's hard to see how, when the people have spoken – as in the end they are bound to – he'll like what they've had to say.