You might find it rather less squishy than you think. Sure, it talks about ideals. That is largely because people who think themselves moved by ideals of the human spirit are more likely to react generously than people who are not.

As for racist assholes, well do you think we should have kind words for the people firebombing mosques and threatening Arab Americans?

But what is the truth of it for me? Well the truth is that any perceptive person mistaken notion that all cultures are to be treated equally is unlikely to survive any real friendship with someone of a different culture. Likewise any silly notion that all people are treated equally in the US is unlikely to survive any friendship with someone of a different race. I am a person who attempts to be somewhat perceptive, and I have definitely named as friends over the years people of different races and cultures. So it should come as no surprise that I am aware of how much the US falls short of its ideals, and I don't have particularly rose-colored glasses.

But still I believe that multi-culturalism in the US is a good thing, and is worth supporting.

More precisely I believe that this is a nation that draws great strength from its immigrants. That tradition is not just (in some vague sense) the right thing to do, but is good for the country in very direct ways. Of course not all imigrants are good for us. But by and large, they work out very much to our benefit.

Think about this. Your average immigrant has generally had to come several thousand miles, has settled in a country that speaks a foreign language, and is trying to set down roots. Very often they have managed to do this while coming from a place where your average person is dirt poor and conditions are pretty desperate. Overall there is a decent correlation between being able to do that and being motivated, intelligent, and reasonably good with money. On the whole those are traits that are pretty good to have in your populace...

Now I won't say that immigrants are an unmitigated good, or that all of them are wonderful people. I am not stupid and I don't ask you to be either. But over the years studies have consistently found that on the whole immigrants put more into our economy than they take out. The outcry goes, "They are taking American jobs!" Well, not really. At first they take jobs that nobody wants. After they can take real jobs, well put a bunch of good workers in your economy, and you improve productivity. Improve productivity, and you wind up creating jobs and raising the standard of living. Jobs are not a fixed resource, rather they are a dynamic resource. Again and again immigrants wind up creating more jobs than they take. (Besides which, their food tastes good...)

Now it may not be pretty good for the rest of the world, but many of the best and the brightest choose to come here. Seems to me that this is a pretty good thing for us, and it is something that the US should want to encourage...