I'm amazed there aren't more LCN mobsters of Irish descent. You're telling me out of thousands of guys, there isn't one who had some Irish heritage? I mean there's Henry Hill who had a non-Italian surname that worked against him, but there's got to be a good few with Italian surnames who have Irish blood. Robert De Niro and Marlon Brando are some of the most famous Italian-Americans out there and they're barely Italian at all; John Travolta is half-Irish. Irish and Italians have been emigrating to America since the mid-to-late 1800s and have gradually started cross pollinating more and more. This isn't reflected within the mafia. Though if a mobster has an Irish mother or is 1/4 Irish on their mother's side, it's probably not in their best interests, perhaps not even relevant, to admit it.

It's actually an interesting question OP. If Tommy Del Giorno can be made when he's half Polish, and if Junior Gotti and Frank Salemme can rise to boss despite having other heritage, then why should a "Tommy Russo" who has a black mother be excluded just because he's half-caste?