TTT
As I've already said - a reaction against liberal policies, the elite, the
establishment and all that entails.
However, should we really lump Trump, Le Pen and Brexit together as if they have some common constituency? Brexit was about getting sovereign power back from Brussels (mainly), Le Pen's root is based on immigration, and Trump campaigned...well, to be honest, I'm still not sure.
Thing is - the liberals/metropolitan elite/establishment (whatever label is currently being used) aren't going to disappear. There will be a counteraction.
It happened in the 50s, 60s, 70s, 80s and 90s.
It's happening now, and will keep on happening, because the western world is fairly evenly divided between liberals and conservatives.
This was proved in this country - there wasn't a landslide in favour or against Brexit.
There wasn't a landslide for Trump.
In fact - there hasn't been a landslide in any major election for anything for ages (that I can recall).
It's pendulum politics.