I once ran a residential course for young people with two other youth workers, both of whom are Jewish, one very obviously so in that he wore a yarmulke, one not.
The theme was anti-racism. The kids were all working class Londoners, about 50:50 black and white with one girl of Indian parentage.
We were worried that she might be isolated and we were prepared to have to work hard to maintain peace between the white and black kids.
My obviously Jewish colleague wanted to share his Friday night traditions with the kids on the first night. My other colleague and I were unsure this was a good idea but he was adamant.
It was a disaster. We had hoped the weekend would break down barriers between the kids - and it did - they became united in an intense antisemitism that was focussed on our very kind, decent and well-meaning colleague.
I'd never seen anything like it - and the only thing that stopped some of the kids taking their anger into a physical attack was my other colleague - who they really liked - telling them that she also is Jewish, and the two of us then talking through the issues with them.
It simmered down a bit but it was still bubbling away on the coach on the way home on the Sunday night.
It brought home to me how deep antisemitism runs in our culture. You do not have to dig very far to uncover it. People will often use casual antisemitic terms or perpetuate antisemitic tropes. Sometimes it's there in people who claim to be politically progressive - hiding behind support for Palestinian rights for example.
I've been a supporter of Palestinian rights for decades. I am opposed to the actions of the Israeli state as are a great many progressive Jews in Israel and across the world. It saddens me when I hear young Jewish Israelis regurgitating anti-Palestinian propaganda that is no different in essence to the sorts of dehumanising stereotypes that fuelled antisemitism - and racism more widely.
The current use of the accusation of antisemitism to smear Jeremy Corbyn is so obviously politically motivated it is hard to imagine how anyone can grant it credence. If Corbyn wasn't so popular, wasn't within a whisker of winning an election these accusations would not be made. He is being attacked in the most extreme way I have seen since the rightwing media attacks on Arthur Scargill and the NUM in the 1984/5 miner’s strike.
The double page spread in the Daily Mail about the secular Seder night that Corbyn attended is a smear worthy of Nazi Germany. We should be asking, who attended that gathering of young radical Jews with the intention of recording and then grossly distorting the proceedings? Who benefits?
The political significance of the likes of the muck-raking rightwing Daily Mail - which has supported fascism in the past - positioning itself as pro-Jewish should be obvious to all people of common sense.
There is a profound risk in using the accusation of antisemitism as a weapon against the likes of Corbyn when it is obvious to anyone with a grain of common sense that there is no credible evidence of him being antisemitic and a mass of evidence to the contrary.
If we attach the label of antisemite to the likes of Corbyn, what will do we call those bigots - who have shelved their antisemitism for the moment because it is politically expedient - when they turn their attentions back to Jews?
There are critically important political concepts that seek to expose the malign operation of power. Applying the term antisemitism - or racism, or sexism or Islamophobia or homophobia or transphobia - to all conduct that you don’t much like, or heedlessly supporting those who use the terms cynically in order to sow division - runs the risk of emptying the concepts of political and theoretical meaning.
It neuters and neutralises them. And there is only one set of interests that serves.