Consider the following scenario. A church newspaper has a Jewish political editor. He reports in his paper on a troubling development. Certain churches support a voluntary body upon whose board sits a man with connections to groups that have declared their intention to wipe every Christian off the face of the earth.
For his pains, the journalist is then ticked off by prominent Christians who support this body and complain he's got it all wrong - simply because he is not a member of their faith which they say means his reporting was skewed.
Would that not be vile? Would it not suggest a degree of prejudice, not to mention sheer irrationality, that would be hard to credit?
Yet switch the religious affiliations around and this is what happened to Martin Bright, the political editor of this newspaper. He had reported that a board member of a community organisation called London Citizens, which was supported by certain synagogues, was a man who had expressed support for Hamas and also had close links to other Islamic extremists.
Bright was then profoundly shocked when left-wing members of the Jewish community told him at a dinner that his reporting might have been better if he had been "more involved in the community" – code for the fact that Bright is not a Jew.
Any rational person would think Jews would be deeply concerned to discover that the community was supporting someone who was in league with the genocidal fanatics of Hamas.
But that's to reckon without the wilful moral blindness of the left. For Jews who parade their left-wing consciences are preoccupied with "Islamophobia", which they equate with anti-Jewish bigotry. But the two are not at all equal.
Hatred of Jews is a baseless prejudice based on lies and fantasies. While some people of course have a baseless and hateful prejudice against Muslims, most of what is labelled "Islamophobia" is instead an all-too-rational concern about Islamist extremists.
But many Jews on the left refuse to make this distinction. For them, all minorities are sacrosanct. So criticism of Islamic extremism, Muslim hatred of Jews or the encroachment of sharia law is "Islamophobic".
Bright says he is baffled that people who consider themselves on the left of the Jewish community are thus making common cause with people on the extreme right of Islamic politics.
Even more astonishing, his fellow diners were saying in effect that the reason Martin saw such extremists as a threat was because he was not Jewish. So it follows that the reason they themselves turn a blind eye to that threat is because they are.
And so they put themselves as Jews on the side of people promoting the destruction of Israel, the murder of Jews and the violence meted out to Muslim women or the threats to the lives of gays or apostates. The reason, however, is surely the very point that has baffled Bright - that his fellow-diners were on the left, just like him.
I have had my political differences with Martin Bright over the years. But he is a fine and principled journalist - and he recognises fascism, including religious fascism, when he sees it.
Which is why he exposes both Islamists who want to destroy our way of life and the useful idiots whom they manipulate.
The left, however, believe they are the sole repository of virtue. All who do not share their views are - in this Manichean formulation - evil and right-wing.
Bright believes in telling truth to power, however inconvenient it may be. But that means exposing Islamic extremism in the heart of a left-wing project. And that is "Islamophobic".
But Bright cannot be demonised as right-wing because he is a man of the left. So these Jews reached for the only other way of neutralising him. They said in effect: "You are wrong because you are not one of us".
Which, for people who stake their reputations on the need to "reach out to the Other", is as ironic as it is repellent.
There is now a terrifying eruption of hysterical irrationality and malice on the left. It was illustrated this week when, in the wake of the appalling Norwegian atrocity, the left seized upon the ravings of a psychopath to assert that those in the resistance to Islamic fascism were guilty of inspiring the deranged murder of scores of innocents.
The attack on Bright pre-dated this particular eruption of the malevolent flight from reason -but its roots are the same.