The belief that every anti-Brexit voter in the UK and every Trump voter in the US is motivated entirely, mostly, or even a little by racism can't be proven. You never know the complicated sources of any particular person's decision-making. I can imagine a hypothetical Trump voter who is indifferent to Mexican immigration and Muslim terrorism, but who is out of work and pissed off at a political and economic system that has failed him or her. Maybe that voter is most turned on by a panache that he or she understands. Maybe he or she just wants to give the finger to an entire group of people who are richer than him- or herself. But whatever. Trump opened his campaign calling Mexicans "rapists". He spews wicked ideas about Muslims and women. Any Trump voter is, on some level, actively willing to forgive that which should not be forgivable in 2016.
I'm sure -- at least I think -- that many British people wish to leave the EU for reasons that don't extend to racism or xenophobia, but I have no way of really knowing that for sure. But I will say that throughout my trips back and forth to Europe since 2002, I have met many British people, who, like anyone anywhere else, can be wonderful and sweet, as well as awful and vicious. And I have heard many British complain about the Poles or Latvians or Lithuanians or Bulgarians who don't want to work or learn English, but who also somehow are taking everyone's jobs, who commit crimes, and whom the British government has to support. I've met well-educated British people who love Churchill unambiguously and ignore his ugly colonialist and racist beliefs. I've seen British tourists maraud -- no other word for it -- through the capitals of Eastern Europe, grabbing local women's breasts, starting fights, publicly urinating and screaming at bartenders about their bills. I've met British people who've bought up property in poorer countries where, by the way, they tend not to bother learning the local language, where they've actively chosen not to even speak to the English-speaking locals.
Yes. The Mexicans and quite a few others have the same complaints about the Americans. I can also tell you that the Croats have the same complaints about the Italians, and everyone -- absolutely everyone -- has the same complaints about the Germans. (Sorry German friends who are reading this. You know I love you.)
(Oh, and I haven't always been a model American ambassador in my own travels, but I don't want to talk about that part.)
They can't all be like that? Of course not and I am trading in some of my own stereotypes. And, yes, even the ones who are like that could be decent, non-racist people in other contexts.
But in retrospect, it should have been obvious to anyone who hung out in Old Town Riga on a Friday night in 2006 that there was a significant number of people from the UK who didn't know what it meant to be a European citizen. It should be obvious to anyone who's hung out in Cancun during Spring Break that there are quite a few Americans who don't know what it means to be world citizen.