you would need to be 100% Italian to ever have had a hope of being made, but "soldiers" were of many ethnic origins. It helped big time if you had a relative in already. And in the Chicago suburbs, many Italians sought a better life style than that of the city, especially for their kids. This included the likes of Sam G, Tony S, and my Dad.
Their was one exception to the Italian rule, and that's the Jewish guys. They weren't strictly considered "familia", but were working associates and sometimes partners. Is that Mafia? I don't really know that answer. I know they never, ever referred to themselves that way. You were working for the "company". at least that's what i was brought up hearing.