‘We have always been very relaxed in our approach to our brand,” a spokesman for Ukip has said. “But as we grow, we find that we have to be much more brand-conscious.” Ukip supporters are no longer allowed to use the brand without express permission from high command; they have been “advised” by the party’s chairman, Steve Crowther, to stay off Twitter. “Remember life before you could delight the whole world with your every passing thought? It wasn’t so bad, was it? I have no Facebook page, Twitter account or Instagram thingy. It’s lovely.”

Crowther’s tone is one of desperate, jocular lightness, but he knows this is no small thing; this is the moment that the firebrands of politics have their lights snuffed out. All those cheeky things that people loved about them – the racism, homophobia, back-to-the-kitchen bigotry, xenophobia – are to be silenced, recast as an embarrassment. And what have they got without their signature devilment? Nothing but a bit of sketchy Euroscepticism that you could get from the Conservative party.

I never agreed with the idea that, just because Ukip support is highest in areas with fewest immigrants, that meant supporters must be idiots, drinking in threats from the Daily Express, which reads more and more like a fevered hallucination. Ukip is a protest party, first and foremost; its headline protest is against immigration, but contained within that is a protest against Westminster; you don’t have to live in an area of high immigration to feel as though you have been left behind by the political compacts made at the centre.

The mainstream has two immediate problems: first, that individual MPs are not allowed to give an authentic response to anything, let alone vote according to their own beliefs and values, without prior permission from the centre. In a coalition, this leads to some truly bizarre iterations – Lib Dem MPs campaigning to save their local library with one hand while voting in cuts to local government with the other. But the opposition is by no means untarnished, also giving the impression that every statement is carefully crafted in headquarters, having previously been focus-grouped to give least possible offence and speak most urgently to your wallet. It’s tedious and, more to the point, impossible to trust. Both the Labour party and the Liberal Democrats have some great individual MPs, yet you would rarely know it to listen to them; their eyes beseech it, while their mouths tell you about clamping down on benefit cheats or hammering immigrants.

Many people, including politicians, cling to the idea that trust has broken down between people and parliament because of the expenses scandal. This is just preposterous: that scandal was due to a stupid system, exploited by a handful of MPs, blundered into by most. Even those who took the dimmest possible view of MPs’ behaviour would have forgiven them by now. The real breakdown of trust is due to the persistent and reasonable sense that nobody is saying what they actually think. That is Ukip’s signature difference: that its representatives don’t have to check with anybody before they give a view. They are mad, frankly, to let go of it. It probably does wound the party, every time a member says something wild about repatriating foreigners, or “hidden” migrants or compulsory abortions for women carrying a foetus with Down’s syndrome, and those wounds probably would, ultimately, be fatal. But to forestall the possibility of those wounds by turning it into yet another party of the mainstream, whose members have to check with the centre before they engage in “social media activity”, is actually worse: just another cynical party, desperate for members but terrified that any of them might give an authentic account of themselves on Facebook.

The second problem is corporatism, the suspicion elegantly expressed in the title of a paper, Whoever You Vote For, Big Business Gets In, by the High Pay Centre, and allied to that a sense that political parties see themselves in business terms, as brands winning brand loyalty rather than people who share beliefs and values and inspire passion.

Ukip has always trodden a dangerous line, appearing to reject post-ideological politics in favour of the very real ideology of nationalism, while at the same time holding extremely post-ideological views (principally, businesses should do whatever they please, for their bottom line, because … business). Its people would not, under close questioning, be able to maintain the fiction that they represented some deeper belief than the same shabby “growthism” their Conservative enemies espouse. Yet they should have at least given it a shot; they should never have started talking of themselves as a “brand” which must be protected as they grew. It is tantamount to saying: “The closer we come to power, the more we will start to resemble those already in power.”

All of this is just tactical; underneath it is a conundrum that is pretty well unsolvable. Ukip gathered a lot of support with its blast of honesty; and yet, honestly presented, a lot of its ideas suggest a poisonous neo-fascism. It would take more than a spin doctor to square this circle.

Yet it would be a mistake to simply watch the discomfort and revel: there is still so much to learn from this spectacle, even as it disintegrates. I cannot help but imagine the party that spoke its views honestly, that allowed its MPs to individuate themselves, that was unafraid of statements that might offend some people, that didn’t necessarily court controversy, but equally didn’t see controversy as a disaster – and was saying something inspiring. It is not, or should not be, the preserve of the far right to dispense with the centrist fiction that we all basically agree and merely have to thrash out some small technical matters to get to the future we want. As Ukip vacates this space, other parties might want to consider moving in.