On 14 June 1956, then-senator John Fitzgerald Kennedy delivered the commencement speech at Harvard University in Cambridge, Massachusetts. “Our nation’s first great politicians were also among the nation’s first great writers and scholars,” he said. “Books were their tools, not their enemies.”

More than 200 miles away in New York, a boy was celebrating his 10th birthday. His name was Donald John Trump.

The jarring contrast between America’s 35th and 45th presidents will be writ large on Monday, when Trump will speak at a wreath-laying ceremony at Arlington National Cemetery to mark Memorial Day. It is not known if he will also pay tribute to Kennedy, who lies in the cemetery beneath Cape Cod granite and an eternal flame, on what would have been his 100th birthday.

The Kennedy centenary is receiving significant commemoration elsewhere. In Boston, his presidential library has opened an exhibit that includes his high school scrapbook, the suitcase he used while campaigning in 1960 and some of his neckties. In Washington, the Smithsonian is hosting exhibitions and programs while his living memorial, the Kennedy Center, has a season of celebrations including, on Monday, readings of his speeches by journalist Dana Bash, soprano Renée Fleming, and actors Brian Dennehy and Martin Sheen, among others. There are also books, magazines and TV specials rekindling America’s love affair with “Camelot”.

The tone is positive and in some cases hagiographic, emphasizing Kennedy’s glamour, erudition and soaring oratory – and preferring not to linger on his extramarital affairs, secret medical problems or foreign policy blunders. Among admirers, the nostalgic yearning is intensified – and perhaps oversimplified – by their contempt for the current occupant of the White House.

The sense of wistfulness was unmistakeable at the recent gala opening of an exhibit of photos from Kennedy’s life and career at the Smithsonian American Art Museum. Nancy Pelosi, the House Democratic leader, was effusive.

We in journalism have never known, and perhaps will never again know, a president who brought such eloquence to prose Gay Talese

“I thought the exhibition was beautiful,” she told the Guardian. “It was really a manifestation of how wonderful the Kennedys always were. It showed history, family pictures and political careers that were to perfection, so I loved seeing it.”

Veteran journalist Gay Talese, 85, told the audience: “For we in journalism have never known, and perhaps will never again know, a president who brought such eloquence to prose and brought to us, even the press – the cynical, cynical press – such a pride in having such a man as our president.”

Apart from a shared mastery of television, Trump is, in many respects, the anti-Kennedy. The 70-year-old Republican, who had no political experience, was the oldest person ever elected US president. Kennedy, a 43-year-old Democrat who had served in the House and the Senate, was the youngest. At the 100-day mark, Trump’s public approval rating was 41%. Kennedy’s was 83%.

Trump was granted five draft deferments during the Vietnam war; Kennedy received military honors for saving the lives of crewmates when their torpedo boat was struck by a Japanese destroyer during the second world war. Trump infamously does not read books, gives disjointed speeches and has claimed: “You have to be wealthy in order to be great.” Kennedy was fond of referencing ancient Greeks and Shakespeare, won a Pulitzer prize for the book Profiles in Courage, and once declared: “This country cannot afford to be materially rich and spiritually poor.”

President Kennedy believed in America as a great civilization, as a moral enterprise, as an evolving set of ideals Stephen Kennedy Smith

Kennedy’s nephew Stephen Kennedy Smith, 59, co-author of JFK: A Vision for America, published to mark the anniversary, studiously avoided mentioning Trump when he said in an interview: “I think President Kennedy believed in America as a great civilization, as a moral enterprise, as an evolving set of ideals, and so he believed in the arts and funding for the arts, he believed in science and funding for science.

“He wrote a book called Nation of Immigrants about how America had been built by immigrants. He gave the greatest speech on religious discrimination that’s maybe ever been given by an American president because he was a Catholic. I think those things speak for themselves.”

The circumstances of Kennedy’s death – assassinated in Dallas in 1963 – are notoriously better known than his birth. He was born in the affluent Boston suburb of Brookline on 29 May 1917 to a family of “great faith, great ambition, great wealth”, as journalist Tom Brokaw put it. He attended Connecticut’s elite Choate Rosemary Hall school – where, incidentally, he never got higher than a C+ for public speaking.

He studied at Harvard University and the London School of Economics, fought in the war and went on to serve in the House and Senate before winning a narrow, still questionable election over Richard Nixon. Whereas Trump’s 2017 inaugural address evoked Nixonian bleakness and put an emphasis on “America first”, in 1961 Kennedy set out an optimistic vision, called for “a grand and global alliance” and set America course to put a man on the moon.

Thomas Henriksen was there that day in a bitterly cold Washington, marching past the new president as an undergraduate of the Virginia Military Institute.

“Our feet were frozen,” he recalled. “We were on the buses, listening on the radio ready to get off, when he made the famous statement about, ‘Ask not what your country can do for you, ask what you can do for your country’. Wow! We were all excited about it. We said, ‘That’s really good!’ It hit the nail on the head. He kind of gave you an uplift.”

Henriksen, 77, is now an emeritus senior fellow at the Hoover Institution in Palo Alto, California. He added: “The Kennedys had a lot of grace. They made you proud of America. This young guy, his attractive wife and two small children. He appeared like the future.”

‘I think he’d be bewildered’

Donald Trump might have “bewildered” JFK if the latter were alive today. Photograph: Jonathan Ernst/Reuters

Kennedy’s presidency of just 1,036 days is best remembered for the low of the Bay of Pigs – when a group of about 1,350 Cuban exiles, backed by the CIA, launched a doomed invasion of their country – and the high of the Cuban missile crisis, when he showed grace under pressure in dealing with Soviet leader Nikita Krushchev and pulling the world back from the brink of nuclear war.

The Republican senator John McCain, who was serving on a nuclear-armed aircraft carrier off Cuba during the crisis, viewed Kennedy as the first president of his generation. “He wasn’t that much older than I was and he certainly was young in appearance,” he said. Asked what Kennedy would think of Trump, the 80-year-old replied: “I think he’d be bewildered.”

Kennedy’s most famous birthday came in 1962, when he was serenaded by actor Marilyn Monroe at New York’s Madison Square Garden. Historians are divided over whether the civil rights struggle and Vietnam war would have taken different courses if Kennedy had lived and not been succeeded by Lyndon Johnson. But with the help of wife, Jackie, the mystique and mythology of Camelot survived him along with a dynasty that followed him into politics and public service.

He was asked by Ben Bradlee … what he wanted on his gravestone and he said, ‘He kept the peace’ Robert F Kennedy Jr

Robert F Kennedy Jr, an environmental activist and son of Robert Kennedy, the president’s brother and attorney general, recalled fondly: “I wrote him a letter when I was, I think, eight years old, asking to come in to talk about the environment. I went into the White House and spent an hour with him in the Oval Office talking about pollution.

“Then he introduced me to Rachel Carson [author of Silent Spring] and to Stewart Udall, who was the secretary of the interior. I brought him a salamander and he walked out with me and we released it in the rose garden fountain.”

Kennedy Jr, 63, added: “I think one of the most important parts of his legacy is his desire for peace and reconciliation with both Soviets and with Cuba and his determination to get us out of Vietnam. All of those things came from an abhorrence that he had for war. He was asked by Ben Bradlee, who was one of his close friends, what he wanted on his gravestone and he said, ‘He kept the peace.’ He said that was the most important job of a president: to keep the country out of war.”

John F Kennedy’s son, John Jr, was killed in a plane crash at just age 38. His daughter, Caroline, 59, served as US ambassador to Japan under Barack Obama. His nephews Patrick Kennedy and Joseph Kennedy II both had stints in Congress and another nephew, Chris Kennedy, is currently a candidate for governor of Illinois.

A great-nephew, Joe Kennedy III, 36, is a Democratic representative from Massachusetts, putting him on the front line of opposition to Trump.

“I think it’s pretty clear the values that he stood for and the vision that he had for this nation are fundamentally opposed by this administration, which is an unfortunate course and an unfortunate turn by the president,” he said. “But for those of us that believe in those values, it’s up to us to make them real and to go out and do better in the next election.”

A view of the eternal flame at Kennedy’s grave in Arlington National Cemetery. Photograph: Brendan Smialowski/AFP/Getty Images

In the age of partisan politics, it remains to be seen whether Kennedy can still be a transcendent figure and whether his centenary can provide a rare moment of unity. There are critics on the right who reject the heroic narrative.

The realities of the Kennedy White House are so extraordinarily scuzzy that Trump is kind of saintly by contrast Niall Ferguson

Niall Ferguson, a British historian and biographer of Henry Kissinger, who was a consultant to the Kennedy White House, said: “I think the Kennedy myth will live on and, the longer it lives, the further it will be removed from historical reality.

“It’s impossible for most Americans to reconcile the image of John F Kennedy that people like Arthur Schlesinger propagated with Camelot and the glamour associated with Kennedy’s presidency with the realities of a razor-thin margin of victory, possibly won with some mafia help, the crazy philandering that even jeopardised national security when it turned that out he and a mobster were sharing a girlfriend with the KGB.

“I almost forgot: we’re bugging Martin Luther King through brother Bobby. The realities of the Kennedy White House are so extraordinarily scuzzy that Trump is a kind of saintly figure by contrast.”

Kennedy was spared the intense media scrutiny that Trump experiences, Ferguson added, while his foreign policy missteps pushed the world to the brink of disaster.

“It’s a chronicle of malfeasance and yet the man is remembered as a hero,” he said. “Maybe there’s hope for Donald Trump yet.”