I've been thinking about this a bit lately and it reminds me of the "melting pot" metaphors we learned about in middle school. Rather than having a bunch of disparate, competing identities I think America is only going to work well when we form a single united, composite identity. I'm not sure if this is nationalism or not, but if it is, it's an ethnically-inclusive nationalism which seems markedly better than the scary kinds of nationalism from the 20th century and earlier. It probably does imply some assimilation, but it's not necessarily everyone assimilating to some "white identity"; rather, everyone assimilates toward the composite "American" identity (whatever that is). I'm not sure if this is what "multicultural" refers to or if it refers to the more progressive ideal of segregated ethnic lanes competing with one another, but the last 5-10 years makes me feel like the latter is untenable.