Ard macha is right - in my experience of Belfast it's the Protestant areas where you find the racism; the Catholic areas are extremely tolerant. I remember one 12 July seeing a marching band that had come over from Glasgow making, en masse, the most disgusting racist remarks at an Asian man, and being loudly cheered on by the local Orange youth. Let's face it, for several generations the Catholics were victims of a form of racism themselves, so they know what it's like. In that sense they are the exception to PeterK's maxim of those on the bottom rung needing someone further down to kick.
Would, however, that there could be some form of reconciliation along the South African lines in Northern Ireland.