[rayiner]

Many people who are "America First" don't just care about the economy, they care about preserving American identity and culture. I immigrated to the U.S. when I was five. I tend to think I fit in pretty well, but my attitudes are definitely different than those of my wife, whose family has been here for hundreds of years. (For example, I have a much higher pain threshold for political and social turmoil given what things are like where I'm from.)

You can, of course, disagree about whether that is a valid or justifiable impulse (and I'd be inclined to agree with you on that). But it's not a mysterious or even unusual one. Heck, we have a founding EU member state on the precipice of fracturing along a linguistic boundary. Certainly, if the shoe were on the other foot and a huge fraction of people running major Indian or Chinese businesses were American immigrants, lots of people would be pretty upset.