At the end of the day, the EU as it is is something that was shoved onto the people of Europe by big business, bureaucrats, Eurocrats etc. Working people feel all the negative impact of open borders and so-called "free trade", and the 1% gets all the gains from it. The mass of people barely feel they have any control over the Parliament of the UK, never mind the even more remote government in Brussels.

Many see the EU as constituted as something concocted by bureaucrats in business and government, for their own ends, a view which I think is correct. So the UK or Greece and the like being fed up with the EU should come as no surprise.

I think the EU as organized is a bad idea. I don't think European integration is a bad idea, but it was done without much consultation of the populace of Europe, and things like this are the result.

In the US, the popular candidates with mass rallies bucking against their party establishments have been Trump and Sanders, although Sanders was pushed aside for the establishment candidate with the help of superdelegates etc. Congressional job ratings for 2016 fluctuated between 13% to 18% approval, 75-84% disapproval. The average American feels alienated from Washington DC because Washington DC is unresponsive to the desires of the average American. The situation is not dissimilar from Europe.