Its what happens when the masses are motivated , especially those who don't usually vote and are not interested in core politics or politicians , until it effects them . Then they vote in a vitriolic/emotional way .
The Brexit and Trump results in my view are just that type of vote , people have been moved to vote in a radical way and give the establishment a kick up the bum , and those bullish type salesman politicians come to the fore , they are listened too by the masses as they make more noise in a radical way, the poor voter thinks he/ she has a voice all of a sudden , in realty they are being used , politics that just demonstrates protests is easy , delivering unpopular decision in power and defending it is the real skill .
I would say the drivers behind the recent voting behaviors are:
Recession impact
Terrorism, in ones backyard
Muslim phobia
Immigration / migration
A feeling that ones country is longer yours or one to control due to globalism
History has many examples of the above motivating the masses to take action or follow a different political path .