Do I believe Jeremy Corbyn is himself an anti-Semite? No
Do I think he's demonstrated a systematic unwillingness to acknowledge or deal with the anti semitic behaviour that's sadly been growing within the party? Yes. Corbyn and the NEC have been very happy to look the other way until public pressure meant they couldn't keep ignoring it.
He can't be held accountable for bigoted nutters in his party making blatantly antisemitic comments. But his willingness to look the other way, and intransigence in dealing with these individuals, has been stark
For example (broader list at the end of the post, source link has links to all the individual examples)
A Labour council candidate in Peterborough, Alan Bull, shared anti-Semitic material online which claimed that the Holocaust was a ‘hoax’. The Labour party was made aware of the posts in 2017, but only suspended the candidate when contacted by the Jewish Chronicle in March 2018."
"Jackie Walker, formerly vice-chair of Momentum, said Jews were the ‘chief financiers of the sugar and slave trade’, criticised security for Jewish schools, and said Holocaust Memorial Day was not ‘inclusive’ enough. After the comments were made and widely condemned, Corbyn shared a platform and campaigned alongside Walker"
Labour shortlisted of a councillor who wrote
"What have the Jews done good in this world"
"The Jews have reaped the rewards of playing victims”
That there are "worse people than Hitler in this world”.
A Labour Party spokesperson said: “We do not comment on internal selection matters"
No comment at all?
The former mayor of Blackburn Salim Mulla, a Labour councillor, was suspended over anti-Semitic comments made on Twitter and Facebook. (suggesting Israel was behind the Sandy Hook massacre and ISIS, and that 'Zionist Jews' were 'a disgrace to humanity'."
He was suspended from the party - but then subsequently reinstated.
This isn't Israeli politics. This is pretty clear cut antisemitism.
Lots more examples here. There's various links for each individual example and allegation here (yes it's the spectator but it links out to multiple sources, if you believe every single one is an anti Corbyn conspiracy then not much I can do to persuade you otherwise)
<a class="break-all" href="http://go.mumsnet.com/?xs=1&id=470X1554755&url=blogs.spectator.co.uk/2018/03/labours-pockets-of-anti-semitism-the-evidence/" target="_blank">https://blogs.spectator.co.uk/2018/03/labours-pockets-of-anti-semitism-the-evidence/
Corbyn’s stated and beautifully expressed desire to stamp out anti-Semitism has been articulated many times in letters and newspaper articles. But that's not the same as actually taking serious and meaningful action.
WRT the IHRA definition of anti semitism
How many other minorities aren't allowed to decide what is racism against them?
The Labour NEC decided what was antisemitism behind closed doors without actually consulting with the Jewish community - the community's views were not invited until after the outcry
Imagine the police, post Stephen Lawrence and the charge of institutional racism, had been given guidelines from the leaders of the black community. Then imagine the police rejected these, instead a mostly white group of police officials, without consultation, drew up its own anti-racism guidelines. Imagine these officials then said to the black community 'here are the guidelines we're following', and when that community complained that these did not address their concerns those police officials dismissed their concerns, responding 'how dare you complain, you should be grateful'.
This is in effect what Labour has done to the Jewish community.