My family comes from an ethnically Catholic background, you know, Italian, Polish, French-Canadian, many of the people who came to the U.S. fleeing the aftermath of WWII, members of the surplus humanity whose livelihood was destroyed by the mechanization of agriculture in the early half of the twentieth century.
In the 1960's and 1970's, in a time when it became unfashionable to attack blacks and indigenous persons, academics such as Mark Granovetter and Edward C. Banfield were writing treatises about the inferiority of traditionally Catholic ethnic groups. And I'll just say that in graduate school, people from these backgrounds find there is no organization for their "national advancement" or "anti-defamation" and they'll be left to their own devices to understand why certain doors just aren't quite open to them.
[Disclaimer: the author of this post has no relationship to the Catholic Church other than having many family and friends who are members, and in fact, is a pagan]