Thank you dears!!
The Italian fascists in the 1920s, as I understand it from places I poked around in yesterday, were Italians who were (in part) reacting to the prejudice they faced here, while Mussolini was doing his thing to bring Italy into a more powerful position in the world. My grandmother evidently was a supporter of Mussolini, before, as my cousin says, 'his true colors showed.' Mussolini was also an activist as a younger man, possibly a communist, his is just a very messy story that I'll need to understand better at some point.
But yes, there were reputable organizations including the Fascist League of North America which was an umbrella for several dozen individual Italian groups. (I don't think they were the same as the Mafia.)
My family research indicates only the very barest tangential connection to anything Mafia-related, which was not uncommon for successful Sicilians to experience. So, the research does not suggest these were the antagonists of this story, and using the Mafia as the villains seems too predictable of a choice besides. Especially if there's another realistic option. The mafia certainly need to be
part of the setting, in some form or other, just like the rise of Mussolini will be, like many other things of note during the years will be.
But I don't think the Mafia are my bad guys.
There are, however, a couple of strange deaths happening in the events swirling around my grandparents, and the 'convenient' timing of those deaths leads me to wonder if they were murders.
The Mafia tended to use guns--like how Rothstein was shot in Park Central Hotel. Rothstein was three degrees of separation away from my grandparents (and directly tied to the Mafia.) But then another guy associated with that same circle of people died, and this guy was
not shot. He was unwell, with stomach pain (death certificate said appendicitis.)
But the timing makes me suspicious... and I wonder if it was actually a hit. If it wasn't appendicitis, but instead poisoning, then it looks from very initial research I did last night that arsenic can cause such symptoms. But who would have poisoned him? He was, according to a couple of newspaper reports, being "blackmailed by Italian fascists." (

Media term, yes.)
So that's when I started wondering if this was an antagonizing force I could use instead of the Mafia. In my extended family's experience, people are always equating Sicilians with the Mafia, and frankly, it's annoying. I don't need to lean into the stereotype, and my research doesn't suggest a strong link between my ancestors and the mafia anyway.
But I wouldn't mind putting fascism into the role of villain, heh.
Two other people involved with events at the time became ill, again at "convenient times," and one died of a heart attack. (The other went to a sanitarium and recovered somewhat.) Naturally, all of this sickness and death could be down to stress of the events underway, but I want to brainstorm other explanations.
For the heart attack victim, who was supposed to take the witness stand in a major case the following day, I was wondering if cyanide might actually have been at play.
Poisons. If poisons are involved here, and if the
fascist leagues were more or less respectable for a time, as suggested by the newspaper reports, and yet some resorted to blackmail, then maybe I can shape a villain from this.
If the guy had been shot, it would look like a mafia hit. He wasn't. He
might (might) have been poisoned. The death (possibly legitimately) called 'appendicitis.' The timing is suspicious.
This is me trying to make sense of it all, and without my coffee yet, no less.