I wonder how many of those moronic xenophobes have worked with some one whose first language is a language other than English. There is a huge canyon between being able to understand/speak a language and having the confidence to do so publicly! And as Delmar pointed out, unlike a similarly situated D, her every accent, every mispronounced word, every Malaprop will be mocked in the entertainment and "news" media.
And answering the question that would naturally occur to any DU-member who might chance to see this post, my Grandmother's first two languages were German and Russian, English being her third; her husband, as I've been given to understand, spoke two dialects of German as well as Russian (and then English). Working in Silicon Valley, I've worked with many whose first language is a language other than English, especially Mandarin, Cantonese, Vietnamese, Korean, Japanese, and Spanish. And many of those co-workers, over the past several decades, understood English far better than they gave themselves credit for.
DU-folk just have a problem with some one from Mexico becoming a US citizen, especially if that person is also somewhat conservative.
Nadin Malaprop chimes in:
More Americans should try to be multi-linguist.