Republican presidential candidate Donald Trump speaks during a campaign rally at the Lakeland Linder Regional Airport on October 12, 2016 in Lakeland, Florida Getty Images

I just returned from a short lecture tour in the US. I was there last in 2010 – but oh my, how different it is now. Gone is that ebullience, the darned 'have-a-nice-day' chirpiness. Instead, in conservative and liberal states, across age, race and class, Americans seemed to be confused or miserable or rattled or livid or ashamed, most of all, fearful. The ground is shifting beneath their feet.

In the Mining Exchange, a charming, old hotel in Colorado Springs (where Donald Trump stayed in August and got stuck in an elevator for 45 minutes) some guests were staunch Republicans who would not be voting for their nominee.

A businesswoman from Denver simply told me: 'Donald Trump offends me as a woman, a Christian and an educated voter. I feel like a stranger in my country. I am scared.' This was before the release of the tape last Friday which showed Trump laughingly tell TV host Billy Bush (nephew of George W Bush) how he felt free to touch women and even grab their genitals.

That tape resulted in a massive loss of support for the billionaire outrider, including some Republican senators and congress representatives. Rudy Giuliani, carries on believing in Trump the saviour, but, by the time I flew back on Wednesday, the previously suave ex-mayor of New York was sounding like a Millenarian hillbilly.

Now come a new batch of allegations of gross, sexist incidents involving the man who would be President of the most powerful nuclear armed nation on earth. The New York Times carried the stories of two women who claimed Trump had groped them foully. One of them, Jessica Leeds, 74, alleged that when she was in her forties, she sat next to Trump in the first class cabin of a plane where he lifted the armrest, fondled her breasts, and tried to get under her skirt: 'He was like an octopus. His hands were everywhere'.

Other media outlets report various invasive Trump behaviours with a Miss USA contestant and a journalist, Natasha Stoynoff who, in 2005, went to interview Trump and his wife. Most disturbing is a 1992, TV Christmas show in which the Republican nominee reportedly says about a ten-year-old girl: 'I'm going to be dating her in ten years'.

Republican presidential candidate Donald Trump hold signs reading, ''Women for Trump' and 'Blacks for Trump', during a rally in Lakeland, Florida. Getty Images

Polls suggest this repulsive man cannot now win. But remember polls can be very wrong. He has vowed to incarcerate Hillary Clinton if he becomes President and to avenge himself on his detractors. Even if he loses, he will claim the vote was rigged and continue to agitate. This is banana republic politics and it goes down well with his ill-informed, easily aroused, discontent, faithful followers. This campaign has marked the end of America as was. Its great myths have been turned to great lies.

Young people I met at the University of Colorado, in homes and public spaces, seemed buffeted by the current tornados of change in their nation. As Jezebel (real name Isabelle), a young art student told me: 'When my great grandfather moved here from Scotland, this country was the future. Now it's the past. He got rich making metal pipes. The American dream. Now there are no dreams. Nightmares, yes. No jobs. No jobs. No jobs. People know they are f****d and still blame the politicians or Hispanics or whoever. Or go shoot some kids in a school'.

True, many manufacturing jobs have gone to nations where labour costs are unforgivably low, but objectively, Obama did turn round the ailing economy he inherited. Then, 750, 000 jobs were being lost every months. In 2014, America created more jobs than in the previous decade. But nowadays, perceptions are more powerful than facts and figures.

The only upbeat young people I met were techies who inhabit an alternative reality. And some who cling on to idealism and hope a more stable nation will be rebuilt after these storms. I can't see that happening for a long time – if ever. When millions of men and women despise most elected leaders, resent the diverse citizenry, distrust facts, expertise and historical truths, are drawn to outrageous conspiracies and boorish, racist, sexist individuals, they permanently disable the functional political order.

In this week's Time Magazine, journalists Charlotte Alter and Michael Scherer have penned an incisive assessment of the current state of the nation. They quote people who really believe Obama is a Muslim double agent, that Hillary Clinton has arranged several murders, that immigrants are stealing cash from 'real Americans', that global warming is a hoax, that white people don't riot, that police, teachers, judges, fact checkers, scientists and economists are all shysters.

Democracy is losing the battle against extreme cynicism. This election has both arisen out of deep national pessimism. God help America.