One thing, Moe: as a first generation Irish american, I've never been called a white ni**er. In fact, I've never heard of any Irish American being called that. We are just considered white and receive all of the privilege that entails.
It's an antiquated term but it has been used in the past. It's referenced in the song "Oliver's Army" by Elvis Costello.
There was a checkpoint Charlie
He didn't crack a smile
But it's no laughing party
When you've been on the murder mile
Only takes one itchy trigger
One more widow, one less white ni**er
