Labour MP Diane Abbott: some describe her controversial letter as 'competitive victimisation', but I see it as an almost inevitable outcome of many marginalised groups all vying for a limited resource: the world's fickle and divided attention. Photograph: Hannah McKay/Reuters Civil rights activist Audre Lorde once said that discrimination “[comes] in all shapes and sexes and colours and sexualities”, and that, among those who fight for liberation, “there can be no hierarchies of oppression”. A self-professed black lesbian feminist, Lorde understood, long before intersectionality became a buzzword, that “any attack against lesbians and gays [was] a black issue [and] any...