Journalists are natural egotists. Even so, we generally prefer not to be at the centre of the news we are reporting. Yet as George Orwell knew, there are times when the journalist cannot avoid being part of the story. Carole Cadwalladr, winner of this year’s Orwell prize for journalism, has made a virtue of this necessity. Not only has she broken some of the most important stories of the last two years, she has also involved her readers in her own voyage of discovery, taking us with her as she navigates the murky waters of the Brexit and Trump phenomena. There is a large personal cost to this: Cadwalladr has been exposed to the wrath of the forces she has been exposing. But it has been a vital demonstration of the power of real journalism. She has not just demanded transparency – she has shown in her own brilliant reporting what transparency looks like.

As the appalling massacre of journalists in Maryland has reminded us, the free press is fighting for its life. One of the preludes to authoritarianism is the undermining of the legitimacy of independent media. The purpose is obvious: to clear the field for far-right propaganda machines. Donald Trump’s systematic targeting of reporters as “enemies of the American people”, the dismissal of all inconvenient reporting as “fake news” and the organised online contempt for the “mainstream media” (which of course does not include approved media giants such as Fox News and the Daily Mail) all serve this same grim purpose. Orwell, of course, would have recognised all of this from the 1930s, and one suspects therefore that he would also have recognised that the bile that has been directed towards Cadwalladr is the ultimate tribute to her effectiveness.

She has had to withstand the full range of attacks, from openly sexist sneering to accusations of professional incompetence, from legal menaces to “jokey” incitements to violence. When Leave.EU posted a video of a sequence from Airplane! in which Cadwalladr’s face was substituted for that of a “hysterical” woman who is repeatedly smacked about the head, the message was as clear as it was crude.

Leave.EU tweets about Russia and Carole Cadwalladr. Photograph: @LeaveEUOfficial

Cadwalladr’s response has been not to hide behind the relative anonymity of print, but to use the word “I” with seriousness and deliberation. She has, as it were, reported on her own reporting, telling us not just what she has found out about the manipulation and subversion of the democratic process in the US and the UK, but how she has found it. The results of her work have been momentous – the exposure of the role of Cambridge Analytica and its satellite AggregateIQ, aided by the culpable negligence of Facebook, in the Trump and Brexit campaigns. But almost as important has been the process – the week-by-week demonstration of what investigative journalism in the public interest really looks like in this radically altered media environment.

For what Cadwalladr has shown is not just what journalism can do but what it must not do. In the face of the onslaught, it is tempting for newspapers to take refuge in an Olympian tone – trust us, we’re professionals. That, of course, suits the far-right narrative of “old media” as detached, elitist, smug. Cadwalladr’s reporting has done the opposite. She has never pretended to know the whole story. On the contrary, she has always made it clear that what she has been trying to do is to identify a few stars in a very dark sky and to map the connections between them so that the constellation of forces shaping contemporary politics gradually emerges. It is a long and radically incomplete task.

This effort is innately and intimately personal. It is, of course, impossible without the long-term support of a media institution, of editors and colleagues. But while that support is a necessary condition, it is not a sufficient one. There is still that unblinking “I”, that personal commitment to discovering and telling the truth about what is being done to our democracies.

Carole Cadwalladr has placed herself on the frontline in the fight to preserve open societies against rich, powerful and ruthless enemies. She has done so with the courage, skill, resilience and undaunted optimism of one who believes that fight can and must be won.

Fintan O’Toole is a columnist with the Irish Times. He won the Orwell prize in 2017