I recall reading a breakdown of the white population of the United States by ethnic origin in this election. Italian Americans, German Americans, and Scots-Irish Americans were more inclined to vote for Trump than those of English or Irish Catholic ancestry. Isn’t Staten Island heavily Italian American? The German American vote for Trump, of German ancestry, may well have helped him in Pennsylvania and the Midwest. Scots-Irish Appalachia, from northern Alabama to western Maryland, went for Trump by minimum 2-1 and often 4-1 margins.
SI is about 35% Italian heritage. Most are backlash types from Brooklyn who moved to SI and who vote Republican. Their parents who lived in Brooklyn and who have mostly died off were FDR Democrats.
I believe Irish Catholics in NYC tend to vote Republican, especially the police.
The current generation of NYC Irish Americans have turned Republican. Call them "whitelash" Republicans. Their parents were most definitely Democrats. The current generation of Irish Americans in MA and RI have not done that yet to any large degree to the best of my knowledge. Perhaps they will in the next 10 years.
With regard to Italian Americans, I note that the two New Jersey counties to the south of Staten Island went for Trump. Is that due to outflow of NYC Italian Americans?
Yes, those areas have many NYC Catholics joining what remains of the original conservatives in Monmouth and Ocean Counties.
Also it appears that the south central portion of Brooklyn went for Trump. Is that an Italian American area or maybe Orthodox Jewish?
Those areas are Orthodox Jews of all nationalities, second and third generation Italian Americans, recent Russian and Ukrainian Christian immigrants, and second and third generation Irish Americans. For example you can see the big and growing concentration of Orthodox Jews in Borough Park, just to the south of Greenwood Cemetery and Prospect Park.
The two small red areas in Northern Brooklyn are the Orthodox Jewish communities in Crown Heights and Williamsburg. Both those areas survived years of decay in surrounding Northern Brooklyn neighbors. Today, they are surviving the latest wave of gentrification in Northern Brooklyn where lots of liberals from around the country have moved into what were once decayed black neighborhoods.