Racism is racism wherever it exists

Dear Sir, — In response to Mr Sherwood, I should like to make it clear that I am not a member of any political party. I am aware that there are plenty of racist incidents besides anti-Semitism and I do not support or condone any of them, but that was not the point at issue, nor does this tit-for-tat approach from Mr Sherwood excuse anything.
I am objecting to two things. One is the rise of anti-Semitism and the other is the deliberate misuse of language and twisting of the facts to support a political argument. 
If Mr Sherwood had read my letter correctly, he would have noticed that I did not accuse Jeremy Corbyn of being a racist; I accused him of failing to recognise a particular anti-Semitic image and of not doing enough to root out those in the Labour Party who express and promulgate anti-Semitism.
Mr Sherwood supports his argument with the following comment from the author Michael Rosen: “The minimum requirements for a claim that there is a ‘problem’ in a given area (eg anti-Semitism in the Labour Party) is that it is distinctly and measurably worse than in other places or in society as a whole. If that hasn’t been shown — and it hasn’t been — it’s not a Labour Party problem, it’s a societal problem.”
What does this mean? That if enough other people are throwing muck at Jews (or any other ethnic group), then it’s okay to join in? And what does he think he means by “a societal problem”? Racism is a societal problem, so that somehow excuses its existence in the Labour Party? So many people are doing it that it doesn’t matter if people in our organisation are doing it as well? Aren’t they part of society, then? 
This is a pernicious argument. Take this to its logical conclusion and where does it end? That it was acceptable for the Milice to round up French Jews and put them in cattle trucks destined for Ravensbruck because they didn’t do it to the same extent as the SS and Gestapo did? 
No, Mr Sherwood. Racism is racism wherever it exists and it is not excusable because other people are committing it. 
Mr Rosen’s argument only seems to reinforce the view that there are some members of the current Labour Party who are in still in denial about what has happened and who are unlikely, therefore, to grasp the nettle. 
I think the person with the greatest ophthalmic challenge, Mr Sherwood, is you. — Yours faithfully,