As a half "irish" person myself, (100 white).. it's a really weird umbrella to be under. I agree with a lot stated here; some are the most outspoken people of hate and bigotry, some are the backbone of city police that have had inclusive recruiting and unfair practices against black and brown populations forever
It's also true with indentured servitude (not "like-slavery" as some Irish-Americans put it when they say, "he had it bad too", they were looked at as bottom of the barrel for a long time. Irish and black people did frequently marry in the 17/1800s, not just here but in Canada, islands etc...
They are oldest 3rd rate whites in this country, but for a long time too not the only ones. Slavs, poles, Italians were all in the same boat of being looked down upon by Angelo society
Why are a good size portion of the American Irish population racist? Well, it's not their culture over here, all that America carried over with its people here are two things, pubs (and drinking), and Catholicism.. I truly blame Catholicism.. the majority of heavy practicing Catholics are the ones that seem to hold white pride or "hold onto their values" about anti-abortion, "their" god first, hold onto this trope of coming from nothing from whose relative that had nothing however many years ago, and no other groups other then fellow Catholics, Italians, did what they did to rise up the American "white" ladder.
My mom has 6 siblings, all are nice to family but there is a big fracture between a group of 4 and group of 3 in terms of American society view as a whole (I have a shyt ton of cousins.) they are conservative as hell and speak like hannity and o'reilly. They marry early, always been religious going, and just different. My family and the three others don't mess with them, and we all like overt liberals (not coli -definition, a political spectrum position). None of these families really go to churn either. My grandma was a sweet lady, really wasn't a churn person her last 50 years. I never heard bs from them, we with all different type of folk, and when I'd hang with them they were too. I'm married to a Jamaican woman with kids, and we get love from those people but thing that bothers we...
We get a lot of love, especially my kids, from those three families that are conservative as hell, like they love taking my sons photo to prove they ain't racist.
Anyways, I truly blame the Catholic Church, even friends raised heavy catholic compared to when we were kids, they were the ones that got racist/conservative views as got older. I'm from philly and Lehigh valley and family mostly from Scranton pa