Nonetheless, the facts seem to be playing little or no part in influencing the anti-semitism narrative. This latest report was thus almost entirely ignored by Corbyn's opponents and by the mainstream media.
It is, therefore, worth briefly examining what the Labour Party's investigation discovered.
Over the previous 10 months, 673 complaints had been filed against Labour members over alleged anti-semitic behaviour, many based on online comments. In a third of those cases, insufficient evidence had been produced.
The 453 other allegations represented 0.08 percent of the 540,000-strong Labour membership. Hardly "endemic" or "institutional", it seems.
Those figures, it should be remembered, have almost certainly been inflated by the efforts of Corbyn's opponents to trawl through Labour members' social media accounts in search of comments, some of them predating Corbyn's leadership, that could be portrayed as anti-semitic.
Intemperate language flared especially in 2014 before Corbyn became leader when Israel launched a military operation on Gaza that killed large numbers of Palestinian civilians, including many hundreds of children
Certainly, it is unclear how many of those reportedly anti-semitic comments concern not prejudice towards Jews, but rather outspoken criticism of the state of Israel, which was redefined as anti-semitic last year by Labour, under severe pressure from MPs such as Berger and Ryan and Jewish lobby groups, such as the Board of Deputies and the Jewish Labour Movement.
Seven of the 11 examples of anti-semitism associated with the International Holocaust Remembrance Alliance's definition adopted by Labour concern Israel. That includes describing Israel as a "racist endeavour", even though Israel passed a basic law last year stripping the fifth of its population who are not Jewish of any right to self-determination, formally creating two classes of citizen.
Illustrating the problem Labour has created for itself as a result, some of the most high-profile suspensions and expulsions have actually targeted Jewish members of the party who identify as anti-Zionist that is, they consider Israel a racist state. They include Tony Greenstein, Jackie Walker, Martin Odoni, Glyn Secker and Cyril Chilson.
Another Jewish member, Moshe Machover, a professor emeritus at the University of London, had to be reinstated after a huge outcry among members at his treatment by the party.Unthinking prejudice
Alan Maddison, who has been conducting statistical research on anti-semitism for a pro-Corbyn Jewish group, Jewish Voice for Labour, put the 0.08 percent figure into its wider social and political context this week
He quoted the findings of a large survey of anti-semitic attitudes published by the Institute for Jewish Policy Research in 2017. It found that 30 percent of respondents from various walks of society agreed with one or more of eight anti-semitic views, ranging from stereotypes such as "Jews think they are better than other people" to Holocaust denial.
However, lead researcher Daniel Staetsky concluded that in most cases this was evidence of unthinking prejudice rather than conscious bigotry. Four-fifths of those who exhibited a degree of anti-semitism also agreed with at least one positive statement about Jewish people.
This appears to be the main problem among the tiny number of Labour Party members identified in complaints, and is reflected in the predominance of warnings about conduct rather than expulsions and suspensions.Far-right bigotry
Another of the institute's findings poses a particular problem for Corbyn's opponents, who argue that the Labour leader has imported anti-semitism into the party by attracting the "hard left". Since he was elected, Labour membership has rocketed.
Even if it were true that Corbyn and his supporters are on the far-left a highly questionable assumption, made superficially plausible only because Labour moved to the centre-right under Tony Blair in the late 1990s the institute's research pulls the rug out from under Corbyn's critics.