Corbyns record for standing in solidarity with minority groupings, including Jews, against human rights abuses over the last 40yrs is open for all to see.
Its his handling of allegations of anti-Semitism within the Labour party that is under fire. I say 'allegations' because while no doubt some moronic attitudes have come to the fore, it is mostly on the fringes and margins of the Labour party.
This, is quite opposite from the allegation of former Labour MP Louise Ellman, who claimed that under Corbyn, anti-Semitism had become "mainstream" in the Labour party - it hasn't. Borne out by the UK Home Affairs Select committee inquiry into anti-Semitism that found that anti-Semitism was less of an issue in British society than most European countries and is not centred with any particular grouping.
"120.Despite significant press and public attention on the Labour Party, and a number of revelations regarding inappropriate social media content, there exists no reliable, empirical evidence to support the notion that there is a higher prevalence of antisemitic attitudes within the Labour Party than any other political party.
121.A representative YouGov poll carried out in May 2016 found that Labour voters were no more likely than voters from other parties to express antisemitic attitudes, with UKIP voters demonstrating the highest levels of antisemitism.
122.Other political parties have not been immune to accusations of antisemitism, albeit apparently with a smaller number of reported incidents,
129.Other political parties must not assume that antisemitic political discourse is an issue affecting the Labour Party alone. The Liberal Democrats in particular should pay heed to the need to act swiftly and decisively to deal with antisemitism within their ranks. We were disappointed by the manner in which their Leader, Tim Farron, referred to disciplinary processes rather than explicitly condemning antisemitic remarks made by members of his Party, "
(Bold is from the publication)
So when I hear MPs leaving the Labour party because of "mainstream" anti-Semitism, I am skeptical of their ulterior motives.
It wasn't just Jewish MPs that left the Labour party under Corbyn.
The anti-Semitic tag is the stick to beat Corbyn with, the real agenda is to stop him entering number 10 and implementing programs of social justice for the people of Britain.