In the spat between Donald Trump and a CNN reporter on Wednesday, I would bet most Americans sided with the president. Who was this rude man refusing to sit down before his head of state? No leader lost votes insulting the media.

The fact is, being rude to Trump hasn’t worked. Hurling abuse for two solid years was supposed to humiliate him and shame him, or at least turn his supporters against him. He was taunted as belligerent, racist, a liar, a sex maniac, a fraudster, a deranged narcissist or merely, in Rupert Murdoch’s reported words, “a fucking idiot”. But he is shameless, and still there.

This week Trump’s Republican party lost control of the House of Representatives, but held on to the Senate and did well enough against the odds of history for him to declare it a triumph. He could afford to gloat. As for ongoing attacks on him from the media, he rightly called it “very good for me politically”.

My file on Trump is crammed with material, on his mental instability, his financial duplicity, his Russian dealings and Stormy Daniels. It portrays a man both unqualified and unsuited for high office, let alone world leadership. None of the material explains why this does him so little harm. When Peggy Noonan of the Wall Street Journal calls him “weak and snivelling … whiny, weepy, self-pitying”, voters seem to sense a fellow spirit. Trump has a frosty wife and scheming children. Mostly he seems lonely and ill-at-ease. The daily savaging in the New York Times invites sympathy for his paranoia. “I am sure everything you say about him is true,” a Trump voter tells a reporter, “but the economy is fine and I think he is a good president.”

When any world leader seems to occupy land beyond the pale of democratic values, it is hard for commentators not to say so. But a fierce debate now envelops the word democratic. Those who know the US know it has two political languages, of the mostly liberal city and of the mostly conservative small town and countryside. At elections, they shout at each other across a contested suburban battlefield. But conservative America currently holds the presidency, and the city has to learn its language or we have six more years of Trump.

Facebook Twitter Pinterest ‘Those who know America know it has two political languages, of the mostly liberal city and of the mostly conservative small town and countryside.’ Photograph: via ZUMA Wire/REX/Shutterstock

Conventional wisdom holds that democracy in both the US and Europe is threatened by so-called populism. Rational and courteous deliberation is being smashed by short-term demagoguery and white identity politics. In National Populism: the Revolt against Liberal Democracy, the academics Roger Eatwell and Matthew Goodwin warn against the myth that populism is “a refuge for irrational bigots, jobless losers, rust belt rejects and angry old white men who will soon die”, to be soon replaced by liberal-minded graduate millennials.

None of this is true. The average income of Trump supporters is above, not below, the US average. Over 40% of white millennials voted for Trump in 2016, and appear to do so still. The same is true of Brexit in the UK. A fifth of graduates voted for it, and a fifth of under-35s. So did half of all women, a third of city dwellers and a third of ethnic minority voters. “People are voting for [immigration control] because they want it,” says Goodwin, not because of their socioeconomic group. It is dangerous to ascribe stereotypes to people just because you disagree with them.

We anti-populists cannot have it both ways. I may feel that the US will see out Trump and survive, like it survived Nixon and the younger Bush. As Arthur Schlesinger wrote, America’s bizarre constitution constantly drives it to the brink of disaster and, at the last minute, hauls it back. I may even look on the bright side, and see in Trump’s presidency a refreshing approach to North Korea and Russia, a reset of world trade, a reality check on Nato. Or I may agree with Trump’s most savage critic on the right, David Frum, that he represents “the most dangerous challenge to the free government of the US that anyone alive has encountered … a third-world kleptocracy”. Either way, the more apocalyptic the forecast, the more critical is an effective response.

My litmus test of democracy has long been capital punishment. Until opinion turned just three years ago, a majority of Britons wanted it back, but were denied it by those claiming it was immoral. For half a century, liberals relied on popular deference, indeed quiescence, to have their way. Trump – and Brexit – show that popular quiescence can no longer be taken for granted. People get angry and want to be heard.

The silence of the majority was a familiar political trope. But social media has given it a voice – the same social media that liberals thought would herald a new democratic dawn. It has brought the anarchy of the mob. As the author David Runciman says, “Mark Zuckerberg is a bigger threat to American democracy than Trump.” Just as free speech needs editing and mediating if it is not to become a daily lynching, so does democracy, through its representative institutions.

A central problem is that, while the right traditionally thinks the left is wrong, the left thinks the right is immoral. Thus the anti-Trump, anti-Brexit champions have found it easier to abandon reason for moral damnation. Trump will never be out-ranted. Now he has half of Congress against him, it must be wiser to deploy argument than abuse. Meanwhile he has taught us an awesome lesson. Let reason go and there will always be a Trump waiting in the wings.

• Simon Jenkins is a Guardian columnist