But "right", "left"; I'm not sure those terms have much meaning any longer. Simon Jenkins proposes that we should talk about "outsiders" and "insiders" instead.
I think Clinton lost the election when she dismissed Trump's army of outsiders as "a basket of deplorables" It was a "Let them eat cake" moment. You don't win elections in a democracy by displaying contempt for the electorate.
The parties of the so-called left have lost almost all contact with the people they used to represent. Which has let in the populist demagogues like Trump and (speaking parochially) Farage. These guys aren't friends of the disadvantaged and dispossessed (they're plutocrats) but they've retained an ability to talk the talk.
I've no idea what happens next. I think Trump is going to engender something like civil war (troops on the streets of major cities) if he carries through on his promise of deportations. Does he think 3 million desperate people will go quietly? Or perhaps- he's an old man after all- he'll settle- as Eisenhower and Reagan did- for playing a little golf.