Susan Dalgety: I've just witnessed the rock-star appeal of Donald Trump

Trumps angry, divisive rhetoric contrasts sharply with the unifying, hopeful speeches of John F Kennedy (Picture: Mandel Ngan/AFP/Getty)

I have never been to an Ozzy Osbourne concert, but I can imagine his fan base. Hordes of old blokes in beards and baggy t-shirts reliving their head-banging youth.

Middle-aged rockers in dad jeans, their wives in too-short, too-tight skirts and their teenage offspring looking embarrassedly excited at the prospect of seeing a legend. And a new army of metalheads – high school rebels in carefully ripped jeans and “Prince of Darkness” T-shirts. Most are blue-collar, everyone is white.

I was in that crowd last night, except it was not Ozzy on the big screen screaming out his greatest hits to an adoring crowd, but Donald J Trump, 45th President of the United States.

He was in Erie, north-west Pennsylvania, on the latest leg of his “2018 Mid-Terms” tour. By coincidence so were we, and it was a gig we simply couldn’t miss. Though we nearly did.

We were among the 3,000 fans locked out of the Erie Insurance Arena after fire marshals locked the doors 90 minutes before the main act arrived, but no-one complained.

Even though many had travelled hundreds of miles to pay homage to their hero, they were going to enjoy themselves, whether inside the venue, or out.

Like any ageing rock star, Trump played all his old hits. “Fake News” was a particular favourite.

“Lock her up,” screamed the crowd in response, every time he spat out “Crooked Hillary”.

“USA, USA, USA,” they chanted as one, whenever he threw them a line.

“We’re going to keep America great,” he bellowed. “Strong! Safe!”

And he has crafted a new refrain that is proving to be very popular.

“The Dems are an angry mob, an angry mob,” he warned in his scariest voice, as his base hooped and hollered.

“Lock them up,” muttered a few. “USA, USA, USA,” screamed everyone.

Susan Dalgety: Trump town is a city of dreams '“ and nightmares

A few hundred yards away, some of the “angry mob” were protesting against the President.

The alternative rally was organised by Caitlin Handerhan and two of her friends. “We are the grassroots,” she explained. “We had to show that Erie isn’t a Trump city. That is a false narrative.

“And he isn’t our President,” she finished, turning to hold up her placard that read: “Nevertheless She Persisted.”

The polite crowd that gathered outside the Peanut Shop was definitely more Coldplay than Black Sabbath, but these people are not the coastal elite Dems that Trump derides, nor the angry mob of his fevered imagination. Just ordinary American citizens afraid for what their country could become.

Speaking to the Erie Times-News, Martha Beoit, of Edinboro, a small college town near Erie, insisted her opposition to Trump was not political.

“I feel, as I tell my husband, that this has gone beyond politics,” she explained. “I believe this is a moral issue. I believe Trump is amoral, and what he stands for, his positions, and the way he treats people are amoral.”

Trump has divided America into two tribes. On his side, the largely white, blue-collar self-anointed “adorable deplorables”, who love him like they would a grizzly old rock star.

Despite Hillary Clinton dismissing them as “deplorables” during the 2016 campaign, these are not bad people, just everyday Americans, looking for reassurance, and little bit of excitement in their ordinary lives.

Trump makes their heart swell with pride when he tells them that they – not he – will make America great again.

He soothes their anxiety when he reassures them that their “real” jobs in coal and steel will prosper under him.

And he panders to their fear of the other when he says he will protect them from “violent criminal aliens” and the “angry left-wing mob”. He stokes up their paranoia, then tells them they are going to be all right while he is in charge.

But there is a limit to Trump’s rock star appeal. More than half of Americans can’t stand him. Nearly two thirds of women now hate him. Their disdain for him is visceral.

The country will find out in three weeks’ time if that disgust is enough to lure the “angry mob” to the ballot box in sufficient numbers to out-vote the “deplorable” Trump fans.

“I need you to show up at the polls,” he pleaded towards the end of the Erie rally, as his staff threw handfuls of red MAGA baseball caps into the crowd. “We will always fight on to victory . . . we are America.”

Fifty-five years ago, another American President whipped up a crowd into a patriotic fervour.

Speaking to 40,000 people in Houston, Texas, only a year before he was so cruelly assassinated, John F Kennedy reminded America why it was so important that they put a man on the moon.

“We choose to go to the Moon in this decade and do the other things,” he said, “not because they are easy, but because they are hard, because that goal will serve to organise and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win . . .”

America realised Kennedy’s promise when, only seven years after his speech, a modest man with Scottish roots took one giant leap for mankind and walked on the moon.

Neil Armstrong, a freeman of Langholm, was born on his granny’s farm in the small town of Wapakoneta in Ohio.

Wandering through the museum that bears his name, only a mile or so from where he grew up, it quickly becomes clear that behind the three men who took off in Apollo 11 was an army of engineers, mathematicians and scientists.

And supporting them was an entire nation, deplorables and angry mobs, united in their limitless ambition for their country.

As Kennedy said: “Our leadership in science and in industry, our hopes for peace and security, our obligations to ourselves as well as others, all require us to make this effort, to solve these mysteries, to solve them for the good of all men, and to become the world’s leading space-faring nation.”

When America comes together in a common endeavour, it is the greatest country in the world. It can go where no man has gone before.

Divided, it is a diminished state, a shadow of its former self. A tired old supergroup, desperately trying to cling on to its glory days, before breaking up over old grudges and missing royalties.

Perhaps it is time America got a new lead singer, one that appeals to Taylor Swift and Beyoncé fans, as well as metalheads.