Americans aren't "xenophobic." I just got back from two weeks in rural Texas and everyone was super nice to me. Nobody was "afraid" that I'm a foreigner. They just don't want me to bring my entire extended family over and in numbers that changes the culture of their home. And people in my dad's village in Bangladesh would hate if some other group did the same thing to them.
People throwing around “phobia” and “ism” is just a way to obscure what they really mean, which is cultural relativism and erasure of the distinction between citizens and foreigners.