The intrusive power of the media, their capacity to lay waste the lives of ordinary people and celebrities alike, has been much aired, before and after Leveson. But there is another form of power, exercised with far greater discretion. This is the ability of the media to shape – and to limit – discussion; a capacity which has in recent weeks become conspicuously transparent, thanks to their efforts to discredit Ukip in general, and Nigel Farage in particular.

The dominant political parties and the mainstream media collusively concerted the attack on Ukip. Never has the management of what is somewhat hyperbolically called "the clash of ideas", conducted by the opinion-formers and gatekeepers of debate, been so clear. Rarely have the tactics to maintain argument within acceptable bounds been more obvious.

Normally so competent in policing the borders of the sayable and the thinkable, the process is largely accepted as a realistic containment of "common sense" within "acceptable" limits. But in the desire to maintain the orthodoxies of the day (which must always pass as imperishable truths), instead of reaffirming the common wisdom, the disseminators of (fixed) ideas have been in danger of defeating their own purpose.

What emerges from the shameful way in which "debate" has been manipulated, is that the hold of the media over the imagination of the people is more circumscribed than its practitioners believe, so maladroit has been their management of political news. Their pride has proved false pride: the threadbare efforts to delegitimise Ukip demonstrates only the desperation with which their overwrought labours are pursued.

First, they trawled through social media postings to find signs of racists in the Ukip fold – those who had supported the BNP, and others who conform to the "fruitcakes, loonies and closet racists" of David Cameron's memorable jibe on radio eight years ago. There was the former Tory who believed the winter floods were a consequence of God's wrath against gay marriage; the man who told Lenny Henry he should go and live in a black majority country if he didn't like the representation of Afro-Caribbeans on TV. There are those who declare Islam a "satanic" religion and some still lost in defunct imperial reverie. It is not difficult to find enunciators of extreme, violent and bizarre views in any party; no such opprobrium has been heaped upon individual members of the "three main parties", although there, too, are rich pickings for anyone in search of what is transformed into mere "eccentricity" by the hallowed status of tradition.

It may be considered something of an irony that, since all the main parties are, in one way or another, conservative parties, an even more conservative party should be the object of such vilification; and this can be ascribed only to the desire to maintain a monopoly of representation by Conservatives, Labour and Liberal Democrats. (That, too, is something of an exaggeration, since politics has become a distinctly non-representational art, a sort of abstract painting of British society.) Alleged European expenses scandals failed to stand up or to dent Farage's popularity; the apparent contradiction of this Europhobe employing his "German wife" was ineffective. The obvious victory of Farage over Nick Clegg in the TV "debate", the unsuccessful sneering at him (which he bore with striking good humour in Have I Got News for You), and the condescending interviews, meant that the net had to be cast wider. A long exposure on Channel 4 news with the Ukip donor, Demetri Marchessini sought to besmirch the party with guilt by association. The "sixth-largest party donor" in 2013 was invited to pour forth his eccentric views, which he did without reserve. He believes that women shouldn't wear trousers, that there is no such thing as rape within marriage and that being gay is about lust not love, since "they go out at night and pick up five, 10, 15 partners".

When, instead of relegating Ukip to the shadows, the party immediately rose in popularity, with more than half the electorate expressing support in eastern England and the West Midlands, there had to be a change of strategy. If they could not isolate Ukip, the media began to embrace him. Farage responded by denying the malign intentions attributed to him. He stressed the number of ethnic minority candidates, and his openness to migrants "who contribute to the economy of Britain". This is respectability by enclosure; modifying excesses by drawing Farage into the fold by a small extension of a centre that veers more and more to the right.

There are at least two ways of regarding these developments. The negative view is the depressing capacity of right-thinking media representatives to tame "extremists", showing that everyone, even the most eccentric dissidents, are susceptible to flattery, inclusion and the kindness of power. Perhaps the rise of Ukip is merely a passing fad, a result of the marketising of politics, a momentary must-have accessory in the great hypermarket of free choice: after all, the surge of the Liberal Democrats in 2010, the brief moment when it was fashionable to be Green, even the rise of the BNP, came and went the way of all flashes in the pan.

A more positive interpretation would be that the ineffectual attempts to destroy Ukip show the growing fragility of the carefully crafted management of what is sometimes called "the national conversation". It suggests that in the future, there may be space for a more genuine plurality of ideas, views and politics than the carefully scripted, staged "rough and tumble" without content that masquerades as democracy in the rich world.

It may be that we are capable of holding something more than mere windblown "opinions" one fine (or rainy) day every five years. It suggests an augmented discussion, a more ample participation in a public life, in which we, the public, have been relegated to the role of bystanders, spectators of our own destiny.