Over time, that "otherness" has always baked itself into the fabric of our country over a couple generations, but there are some particular challenges for this wave. Mainly skin color and strong religious differences (for Muslims).
The whole "Spanish language everywhere!" problem is generational. First wave Italians didn't speak English either, but their children did.
So I think the anti-immigration vibe is nothing new and part of the process. Liberals might be making things harder by pushing for cultural preservation/independence rather than (through indifference) encouraging assimilation. I don't think supporting different cultures living side by side ever works out long term. If we either side can stop being so extreme in their approach, maybe we can continue our national process of assimilation and (begrudgedly) open arms to immigrants.
There is nothing in American anything like the segregation North African Muslim immigrants face in Europe, even in the densest Muslim communities. That's what "independence" looks like. What are we so afraid of here?
I think you understated the similarities between Americans and Irishs / Italians, and understated the differences between Americans and Hispanics / Muslims. Not sure whether you did this intentionally, but it is so obvious that Americans / Irishs / Italians are part of western culture, they have differences, but they belong to one big group. On the other hand, Southern American / Middle East belong to non-western culture. The latter is even worse, it is anti-western culture. When you look at the countries, US / UK / EU countries are similar, but Southern America countries are different from US / UK / EU countries, and Middle East countries are extremely different. Did you intentionally blind yourself?
Also, we lived in a different time with two important changes: 1. welfare state. 2. far-left ideology (multiculturalism, post-modernism, etc.) becomes norm
Apart from a shared complexion --- a complexion, by the way, that we used to dispute was "white" in the case of Italians --- what ties a Irishman to an Italian?
In those terms, talking about the offsetting "whiteness" with Latinos takes on a more sinister meaning --- albeit one I'm sure most of us never consciously intend. What it really means is "why can't we just keep keeping disfavored ethnicities out?".