These days it’s all the rage at the ABC to talk about, and advocate for, diversity. That’s fine. The only problem is that, when leading figures at the taxpayer-funded public broadcaster refer to the need for diversity, they ignore the importance of political pluralism.

In The Australian last Monday, Sophie Elsworth reported on the journalism event held at RMIT University in Melbourne. It took the form of a discussion between former ABC journalist Barrie Cassidy (who currently holds the position of adjunct professor at RMIT) and Patricia Karvelas (presenter of the ABC Radio National Breakfast program).

According to the RMIT Journalism Twitter stream, Cassidy kicked off by stating the media “is putting democracies around the world at risk”. He went on “to point a finger at Fox News right off the bat”. How predictable is that? A left-of-centre journalist criticises a Rupert Murdoch news outlet.

Needless to say, it soon became one of those occasions, so familiar on the ABC, where everyone agrees with everyone else in a left-of-centre kind of way. This became evident when, in response, Karvelas asserted: “Fox News aren’t political journalists. They are partisan lobbyists.”

Clearly, she is ignorant of the fact that throughout the day Fox News provides one of the best news services in North America – as its coverage of Russia’s invasion of Ukraine attests. It is only at night that Fox News’ opinion programs – presented by the likes of Sean Hannity, Tucker Carlson and Laura Ingraham – commence and many of them contain serious debates.

Elsworth reported Karvelas as having said: “Diversity is when it’s not always a white man that’s running the newsrooms, that to me is diversity and that’s happening but it’s slower.”

Later on, Karvelas warned of “the same pool of people” in the media and referred to the prevalence of “white private school people” in the industry.

So that’s clear, then. To Karvelas, diversity is achieved when race, gender and class mix. A difference of political, religious, social or cultural views is not essential to diversity in her view. That’s the kind of mindset journalists get when they work in a conservative-free zone like the ABC – where there is not one conservative presenter, producer or editor for any of its prominent TV, radio or online outlets.

Take Karvelas, for example. She recently took over from Fran Kelly as presenter of Breakfast; just a handover of one green-left journalist to another. It is difficult to think of any political, social, economic or environmental matter on which the two would disagree. Likewise, it’s hard to imagine Cassidy would differ with them in his views on any significant matter.

David Anderson is the ABC’s managing director and editor-in-chief. As such, he is responsible for Karvelas’s appointment. Jane Cadzow wrote a profile on Anderson published in Good Weekend on February 27 last year. At the time, Karvelas was presenting the Radio National Drive program along with Afternoon Briefing on the ABC TV news channel.

Karvelas told Cadzow: “David will text me and go, ‘you went in so hard on that minister, wonderful’.” Cadzow reported Karvelas hastened to add that this does not mean Anderson is against the government but that “he encourages you to do vigorous journalism”.

For his part, Anderson told Cadzow: “We upset all sides of politics, simply by holding people to account.” It’s true ABC journalists criticise both Coalition and Labor governments, but invariably from a left-wing position. Anyone who spoke about the ABC with former Labor prime ministers the late Bob Hawke and Paul Keating knows this.

The point is that, contrary to Anderson’s view, there is no evidence the ABC upsets the Greens’ side of politics, except for the occasional criticism that its journalists are not sufficiently left-of-centre. Also, the so-called “Voices of” independents, who are contesting only Coalition and not Labor seats at the forthcoming election, have had very soft coverage on the ABC and in Nine newspapers.

The essential problem with the public broadcaster is that it’s effectively a staff collective that is run by journalists and not by management. It’s only management that can change the ABC’s conservative-free-zone culture.

This culture change cannot be achieved by the ABC board or by its chair, currently Ita Buttrose. The only key role the ABC board has with respect to the organisation’s culture is to appoint the managing director.

Anderson, like many ABC managing directors before him, has subsumed the ABC’s in-house staff belief that true diversity can exist without political diversity. That’s why ABC management goes into denial when it is suggested there are no prominent conservatives within the ABC and that the public broadcaster has “cancelled” a number of prominent conservatives who are not invited by presenters and producers on to ABC platforms.

In 1968, German-born American Marxist philosopher Herbert Marcuse published his influential essay, titled “Repressive Tolerance”. He advocated “intolerance against movements from the right and toleration of movements from the left”.

These days very few people have heard of Marcuse. But this concept of repressive tolerance underpins the current cancel culture that pervades many publicly funded institutions, including the ABC.

This weekend the Sydney Opera House is host to the All About Women conference. On Thursday, Larissa Behrendt, a co-founder of the festival, told ABC Sydney radio presenter James Valentine the organisers have ensured “that we have a diversity of voices and views and a range of voices that are going to engage and challenge”.

In fact, a glance at the speakers’ list reveals that there is barely a conservative on the two-day program. Australian speakers include Clementine Ford, Laura Tingle, Anne Summers, Yumi Stynes and Julia Zemiro. You get the picture.

Behrendt believes that All About Women’s conservative-free zone happens to represent diversity – as if no conservative women exist. Karvelas and Cassidy hold the same view about the ABC. This leads to a toleration of left-of-centre views and a censorship of right-of-centre views. The Marxist Marcuse would be pleased.