Here is the letter in full for people who want to read it...
Racism is black and white
Tomiwa Owolade claims that Irish, Jewish and Traveller people all suffer from “racism” (“Racism in Britain is not a black and white issue. It’s far more complicated”, Comment). They undoubtedly experience prejudice. This is similar to racism and the two words are often used as if they are interchangeable.
It is true that many types of white people with points of difference, such as redheads, can experience this prejudice. But they are not all their lives subject to racism. In pre-civil rights America, Irish people, Jewish people and Travellers were not required to sit at the back of the bus. In apartheid South Africa, these groups were allowed to vote. And at the height of slavery, there were no white-seeming people manacled on the slave ships.
Diane Abbott
House of Commons, London SW1