DONALD Trump seems to be exacting some kind of sweet revenge on the genteel folk of Palm Beach, Florida – and they’re not happy. If you’ve never heard of this place, that’s exactly how the people who live here like it. Three drawbridges, which rise for passing yachts, isolate the town from the rest of the world and keep the riff-raff at bay – as one observer once put it, in case of insurrection on the mainland.

Welcome to America’s most exclusive community – “the island”, as locals call it. This balmy, sun-drenched 13-mile spit of sand, 90 minutes' drive north from Miami, is a village of the privacy-obsessed and gaga rich. Around 30 of the 400 wealthiest people in the world own property in here, as do celebrities including Rod Stewart, Jimmy Buffet, Celine Dion, and tennis stars Venus and Serena Williams.

Palm Beach is also the town where President Trump happens to have a place called Mar-a-Lago – the golf resort and country club that has become his winter White House, or as some observers now call it, “White House South”.

Since being sworn in on January 20, Mar-a-Lago weekends have become a staple of the Trump presidency and last week it hosted a summit between Chinese president Xi Jinping and Trump. It doesn't get much higher profile than that. For many of the denizens of this ordinarily tranquil and well-behaved town, this newfound fame hasn’t been a pleasant experience.

Each weekend the president spends here – five out of 10 so far – security protocols have closed bridges, clogged thoroughfares and blocked roads, essentially cutting the south of the town off from the north.

On top of that, small armies of protesters often show up when the president is in residence, as well as supporter groups wearing “Make America Great Again” caps and media crews. Not only has this added to the traffic congestion, but it has also been blamed for lost sales to businesses, dozens of restaurant cancellations and widespread frustration.

However, the most destabilising effect is the sudden abundance of unwelcome attention from the outside world.

These disruptions cap a private, 30-year war that Trump and the blue-bloods here, who dominate Palm Beach, have waged on one another. Now that he is the president, some here say Trump is relishing their current displeasure.

Most people here will tell you – even Trump supporters – that the brash, loud-mouthed, self-aggrandising New York property tycoon has never fitted in. He may be a billionaire, own Mar-a-Lago and even be the leader of the free world, but Trump has a bellboy’s hope in hell of ever garnering the kind of pedigree required here.

His response back in 1990, when asked in a Vanity Fair article if he was bothered at not being invited to join the exclusive Bath and Tennis Club (lovingly known as the B&T): “They kiss my ass in Palm Beach. Those phonies.”

The deeper you dig, the more ironic it seems that most Palm Beachers voted for him.

To better understand the often-unfathomable mindset of Trump, his strange relationship with Palm Beach offers fascinating insights.

On Saturday, March 18, the president was in town and I made my way to the island. According to Google Maps, the place was on lockdown with all three bridges blocked.

That turned out to be what Trump might call “fake news”. Two of the bridges were open. Only the southernmost bridge, the one closest to Mar-a-Lago, was closed.

The previous evening, an hour before the president’s arrival, an underage driver in a white Dodge Charger sped past the roadblock on South Ocean Boulevard toward Mar-a-Lago and crashed into a fence. According to police, the teenager was both suicidal and “armed and dangerous”. A baseball bat and a metal pipe were found in his car. A police spokesman also said the youth had previously called in terrorist threats to CNN.

Given that incident, presidential security on Saturday morning was surprisingly light as I attempted to cross the southern bridge. A policeman stood chatting with a security officer near two parked black SUVs, behind an electronic diversion sign that steered cars back the way they came.

I arrived via the middle bridge, crawling my way through the congestion on Royal Palm Way and cruised around Palm Beach’s little streets to get a feel for this unique bastion of uber wealth.

Henry Flagler, one of the founders of early oil giant Standard Oil, dreamed up Palm Beach in the 1880s. Enchanted by its tropical environment and offshore distinction, he created a winter retreat for the cream of New York’s industrial wealth – the Carnegies, Astors, Vanderbilts, Mellons and Rockerfellers among them. Many of their descendants have remained.

Most of what you see today was built in the Roaring Twenties, although Palm Beach was already a resort town with lavish hotels such as the Breakers (built in 1896) and grand residences modelled after stately palaces in Europe. The architecture here owes nothing to the gaudy tropical villas of Miami. Palm Beach is definitely more Tuscan palazzo than Scarface.

I drove past the B&T, the Sailfish and the Everglades club at the foot of glittering Worth Avenue, the high-end shopping boulevard – all notoriously discriminatory country clubs, although Palm Beach insiders say those policies no longer apply. A member was once suspended from the Everglades for bringing Estee Lauder because she was Jewish, and Sammy Davis Jr was ejected because he was black and Jewish.

The priciest mansions begin on South Ocean Boulevard, on the Atlantic shore. The most expensive home on the market today is a seven-bedroomed, 10-bathroomed, 14,318sq ft mansion at 100 El Bravo Way with a price-tag of $25.5 million (£20.4m) – although a number of homes are worth a great deal more than that.

But it’s difficult to see much of the private residences. Only occasionally, spying through a driveway entrance, will you see these giant villas rise up before your eyes. Most sit behind manicured 15-foot hedges, hidden from visiting voyeurs and reflecting the town’s fierce obsession with privacy.

Along with scions of American industrial wealth, John Lennon and Yoko Ono once owned property in Palm Beach, as did the Kennedys. This was where a postal worker tried to assassinate JFK after he beat Richard Nixon in the 1960 presidential elections.

Conrad Black, the disgraced Tory peer and former Daily Telegraph owner, also had a home here, before his 2007 conviction for defrauding investors. Lord Black was a keen observer of life in Palm Beach, and once said he had witnessed a Rolls-Royce Silver Cloud smash into the back of a Rolls-Royce Silver Shadow, which smashed into the rear of a Rolls-Royce Phantom V at the corner of Worth Avenue and North County Road.

Despite that, everything in Palm Beach, including its money, is understated – the antithesis of Trump. Yet you could roll a ball down Worth Avenue and easily strike 10 millionaires, and maybe a billionaire or two if you’re lucky.

The biggest and grandest mansion of them all in Palm Beach is Mar-a-Lago, which Trump bought in 1985.

Build by the breakfast-cereal heiress and socialite Marjorie Merriweather Post in the 1920s, it was the expression of “an American in love with the artistic splendor of Europe ... Hispano-Moorish tiles of Spain; the frescoes of Florence; Venetian arches to introduce and frame water passages ... and a 70-foot castle tower for unimpeded panoramas of sea and sky”, according to Town & Country magazine.

It was originally Post’s idea for the estate to be used as a winter White House and willed the property to the US government in 1973 to be used as a presidential getaway. But the government didn’t want the upkeep cost, so it returned the property.

Trump originally offered $28m for the property, but it was rejected. So he bought the beachfront directly in front for $2m and threatened to build a wall to wreck Mar-a-Lago's views. “That was my first wall,” he told the Washington Post. “That drove everybody nuts. They couldn’t sell the big house, because I owned the beach. So the price kept going down and down.”

In the end Trump snapped the place up for $7m.

As a testament to Trump’s business acumen, he restored all 126 rooms, added a 20,000sq ft ballroom and turned the library into a library bar, where he hangs the giant portrait of himself in tennis whites. It now brings in revenue of about $25m a year from membership and rental income for public events such as weddings and fundraisers.

Above the door to one of those restored rooms is the name Mary Trump, the president’s late mother, who in the late 1930s travelled from Lewis to New York, where she met Trump’s father, Fred. This is the room where she most often stayed when she visited Mar-a-Lago.

Unlike the B&T or Everglades, you don’t need the right religion, colour or pedigree to be admitted. The non-discrimination policy brought with it a different class of member – Jews, blacks, energy drink magnates, sports team owners and struck-it-lucky hedge funders. If you have the £160,000 joining fee, and £11,000 in annual dues, you’re in.

A few of the old guard began coming along also. One Palm Beach insider, Anne Obolensky, a member of the Russian royal family who grew up in Palm Beach and is a Trump supporter, says: “He essentially saved Mar-a-Lago. I knew Marge Post and her family. Maybe because I was younger, I always found the place scary and dark, and there were all these tapestries around the walls. He did an incredible job renovating. It's much better than it was before. It's a jewel now.

“Sure, the old money didn’t like him. The old guard, the ones with the enormous money, wants everything to be quiet and discreet. Then all of a sudden you have a man like Donald Trump, who likes to be visible and talk about himself.

“It was a big cultural difference. So they didn't want him in the clubs and that’s when I think he just said, 'Watch this.' And he made his own club.”

Asked what she thought about the way Trump acquired Mar-a-Lago, she says: “It was business. That’s all.”

Obolensky adds: “As he got more successful, a lot of people just said, ‘What the heck. It's a pretty place and they have really good food, so let’s just go and have fun.’”

These days, despite heavy security, members and their invited guests get exclusive access to the president of the United States and sometimes a grandstand view of world events. Just a few weeks ago, in Mar-a-Lago’s public dining room, Trump and Japanese Prime Minister Shinzo Abe scrambled to respond to a North Korean ballistic missile test. Meanwhile, Trump got global attention on his club.

Walking into Starbucks on Worth Avenue feels like a scene from the Great Gatsby – but 60 years on. This is where the Jay Gatsbys of the world come when they’re older, and they still play a set before lunch at B&T, drink their gin and tonics at the Breakers and take an evening supper at the Everglades.

Almost nobody in Palm Beach will talk on the record. Elizabeth Clarke, the editor of the Palm Beach Daily News, which has covered Trump’s local feuds and lawsuits, as well as the social scene at Mar-a-Lago, for more than 30 years, says: “People come here for privacy and security. If you suddenly have the whole world’s eyes on you all the time, it gets tiresome.”

One Palm Breach resident, who asks that his name be withheld, says: “Not many people knew anything about Palm Beach, which is what we like about it. Now it’s like a bullseye – not just for visitors, but possibly even for terrorists.”

“Yes, there are lots more tourists,” he adds. “But a man with three kids and a van is not exactly the target audience. Lots of rubberneckers, which really isn’t any good for business on Worth Avenue.”

Mark Ford, who runs a publishing consultancy in nearby Delray Beach and visits Palm Beach socially, says: “The practical aspect of the whole thing is a nightmare – the traffic, the road blocks, the security – but I can tell you why most Palm Beachers voted for Trump. Even if they don’t like him, they voted for him because they want a tax cut.

“Most people in Palm Beach are retired and live on a fixed income – albeit a high one. So any whiff of a tax break or a rise in interest rates gets their support.”

Another resident, a former banker from Manhattan, is waiting for his wife outside the Chanel store. He says he has played golf at Mar-a-Lago and has also eaten there.

“It was very nice,” he says. “Trump likes to work the crowd at dinnertime and greet people. My wife thought he was like a glorified maitre d’ who imagined himself bigger than he really is – but I found him polite and very gracious.”

Clarke says she’s heard that one too from a few people here, the likening of Trump to a jumped-up maître d’. And there it is, the perfect encapsulation of a class barrier never to be breached by Trump, and by extension the nearly 500 members of Mar-a-Lago, who may not be welcome at the Everglades or the B&T.

In many ways, Palm Beach is Trump’s ideal playground. He doesn’t simply seek attention, he craves confrontation and this subtropical barrier island off the Florida coast uniquely fits the bill.

Since his arrival here, he has breached every Palm Beach sensibility imaginable – from large-crowd events in the gardens of Mar-a-Lago to big groups of noisy children.

In 2006, in a prophetic sign of a political strategy to come, Trump hoisted a giant American flag up an 80ft pole on the grounds of Mar-a-Lago defying Palm Beach bylaws on flag size and height. Local rules dictate no flagpole can be taller than 42 feet.

The town fined him $250 a day while the flag remained up. Meanwhile, he went on CNN to say: “I just get letter after letter saying, ‘Please fight, please don't let them take down the American flag, it's a disgrace.’ We gotta preserve the sanctity of the flag.”

Earlier that day, CNN sent a team to the B&T, which was rebuffed by a valet. Reporters later spoke to a shoeshine man, who told them members thought Trump's big flag “made the whole area look like a used-car dealership”.

Trump sued the town for $25m over the flag dispute – but eventually dropped the case when his fines reached $120,000. The flag was lowered, but Trump pulled another publicity coup from his hat, promising to donate $100,000 to veterans’ charities.

Then there was Trump’s legal action claiming the town had discriminated against him because he allowed black people and Jews to become members of Mar-a-Lago. Another was his $100m lawsuit against Palm Beach International Airport over the noise caused by planes flying over Mar-a-Lago, which was only dropped in November last year, just after Trump won the election.

Obolensky says: “His way of doing things is very Russian – which could explain his affinity with Vladimir Putin. He likes to set off a small bomb in one place and then negotiate the fallout somewhere else. I admire that.

“I do think he likes Palm Beach for more than the confrontation. Where else would he find a place like this? He's already risen to the top of his own building. In this country, where else is there to go? He already owns big parts of New York, arguably the greatest city in the world. He has businesses everywhere. When you’ve done all that, Palm Beach is really the only place left in America.”

She adds: “Sure, there are clashes – and he usually wins. I think he enjoys Palm Beach very much.”

Meanwhile, as palm trees sway in the sea-breezy heat, Trump’s revenge seems complete, especially now that he’s the president. But those old Palm Beachers are a resilient bunch – and, no doubt, in some British colonial mansion or Tuscan villa, they’re biding their time over gin and tonics, as the ocean before them churns dollar green.