The people at the top felt very much so - people lower down had rather less objections to their kids marrying someone who wasn't 'their own kind' --- as long as that the potential spouse was a good deal better off and socially more established than themselves.
But in 1940, the numbers of (non-Italian/non-Jewish) New Yorkers who felt that Manhattan was much better off, not worse off, because of its many Italians & Jews were a small (if hardly shy) minority.
Praising inclusive values as a wonderful attribute for a particular society was simply not on under Modernity.
School teachers, preachers and newspaper editors, who along with Mom and Dad, set the tone, did not praise or preach it.
Popular Eugenics peaked during War Years
Indeed popular eugenics (dividing all into lives worthy and unworthy) was at its very apogee in those early war years, along with an Isolationist-directed rejection of all war refugees who weren't upper class, wealthy or celebrated in science and the arts.
Later in the war years, widespread race riots broke out against blacks and Latinos and popular anti-semitism reached an all-time peak, albeit in a mostly hidden manner.
All this goes a long way to explain when details of The Holocaust were reported in accurate detail to our grandparents by the media, while it was still happening, still virtually nothing was actually done to try to stop it or bring refugees from it into America.
Everyone in the world - on or off Manhattan - agreed that the tiny island held an extraordinarily large and mixed population of ethnicities, religions, skin colors and lifestyles normally kept very far apart.
Something unique in the history of the world.
Manhattan found itself in the middle of the war's most important front line - which was the battle over moral values - whenever people reflected for a moment on whether this mixed up impurity was a very good thing ---- or very bad thing ...