When anger meets bigotry, the outcome could be President Trump, as Matt Frei’s campaign-trail documentary makes clear.

From the hair alone you may infer the Donald. Ridiculous, unconstrained by normal rules of reason, taste and decency, and yet, against all the odds, surviving.

So we must turn, with darkening eyes and heavy hearts, to the documentary by Channel 4’s Europe editor Matt Frei, which posed the question that would have seemed as ridiculous as the hair even three months ago – President Trump: Can He Really Win?

Frei follows Trump on the campaign trail as the bumptious billionaire promises to pay the legal fees of anyone disposed to “knock the crap” out of any press at his rallies, calls Hillary Clinton “in a certain way, evil” and asks his followers – who call his campaign “a movement” – rhetorically, “Is she crooked or what?”. All while he lays out his three-point plan to make America great again: ban Muslims from entering, deport 11 million illegal immigrants and – most famously, risibly and so far effectively – build a wall between it and Mexico.

The documentary is a comprehensive tour of what someone unfettered by interests other than his own can do by tapping into a groundswell of genuine and legitimate anger (among the increasingly disenfranchised white working class – three-quarters of Americans, as journalist and author Ron Suskind pointed out, effectively haven’t had a pay rise in 40 years), and bigotry that is aggravated when people are under pressure. He promises much; he sounds, if not authentic, then at least different from and “realer” than his establishment counterparts on each side of the political divide. “He’s his own man,” says one supporter, “doing it for the American people.”

Frei ably outlined Trump’s progress, the ingredients of his success, the disapplication of normal rules (such as the fact that some evangelical Christians are swarming around a thrice-married candidate who “doesn’t want to get into specifics” when quizzed about his favourite Bible verse) and the problems he is causing for the Republican party. But nothing spoke more eloquently than the look of barely controlled fury on the face of the Republican national security adviser, Commander Bryan McGrath. “The man is charting a course that will exacerbate America’s decline in the world and will create civil unrest within his border,” he said, spitting the words out as if he wished every one were a bullet aimed at the Donald’s heart. “This is what we’re stuck with.”

Meanwhile, Trump continues to win primaries and gather support with promises such as the one to “bring back waterboarding – and a hell of a lot worse!”. Democratic congressman Luis Gutiérrez insists that in 2016, you can’t spend a campaign insulting and alienating Muslims, immigrants, women, African-Americans and anyone else who doesn’t look exactly like you, and still cobble together an electoral majority at the end. Next to McGrath, he looked like a mindlessly blind optimist. After everything we had been shown, it didn’t seem at all too much of a stretch to think that 2016 might be exactly the year you could do that.

~Lucy Mangan