I don't understand how you can continue referencing narratives like this one, wear your minority identity on your sleeve like you're still competing in the DEI Olympics, but yet keep failing to see that you're personally responsible for doing exactly as this book bemoans.
If you're really concerned about preserving American culture against dilution by immigrants bringing other cultures, have you ever thought that maybe it's time for you personally to hold back with the developing-country-style populist strongman boosting? Not some vague "other" that might come here and do even more of the same, but you personally, right here, right now.
If this lauded western European culture is based around consensus, process, and compromise (rough points you've made elsewhere about the importance of culture), surely you can recognize that this culture has something to say about the wisdom of attacking longstanding allies (regardless of any perceived immediate benefit). Essentially, if you see value in the incumbent culture then maybe you should be content deferring to it a bit more while you're still assimilating.
I'm sure you're going to have rationalizations aplenty in response to this comment, so all I can really say is perhaps try some self-reflection.