Charles Krauthammer was 22 and had just completed his first year at Harvard Medical School when he dived into a swimming pool and, unaware that somebody had moved the springboard so that it extended over the shallower part of the pool, hit his head on the bottom.

Paralysed from the neck down, he spent the rest of his life in a wheelchair.

“If I can just muddle through life, they’ll say it was a great achievement,” Mr Krauthammer later suggested. “That would be the greatest defeat in my life if I allowed that.”

One of America’s foremost public intellectuals, Mr Krauthammer, who died last week from cancer, emerged victorious over the hand that fate had dealt him.

“I leave this life with no regrets,” Mr Krauthammer wrote earlier this month in a typically eloquent yet plain-spoken final message to the readers of the weekly Washington Post column he had penned for the last three decades.

In all, he produced more than 1,600 columns for the newspaper. Witty, erudite, forthright — and, occasionally, touching and self-depreciating — they earned him a Pulitzer Prize.

As the Post’s obituary proudly noted, Krauthammer, who was the son of Jewish refugees who fled the Nazis, was also “a marquee essayist for magazines across the political spectrum” and a “near-ubiquitous presence on the cable news”.

But while Krauthammer, who drove himself around Washington in a specially adapted van that he operated while sitting in his motorised wheelchair, was unique in many regards, his political journey was one that has been travelled by many Jewish conservative intellectuals since 1970s.

In the same year as Krauthammer’s accident, George McGovern was nominated as the Democratic party’s presidential candidate. His selection stirred an emerging movement of New York liberals — at the vanguard of which were journalists, writers and academics such as Daniel Bell, Norman Podhoretz, Irving Kristol, Ben Wattenberg and Seymour Martin Lipset — who had become increasingly disillusioned at the turn the American left had taken in the late 1960s.

They shared what the sociologist Nathan Glazer termed “an allergy toward Communist oppression” with a disgust at the radicalism of the counter-culture and a growing anxiety that Great Society anti-poverty programmes were doing more harm than good. They were, quipped Kristol, liberals who had been “mugged by reality”.

In what they characterised as McGovern’s neo-isolationist foreign policy and his apparent appeal to the New Left, these neoconservatives found all of their worst fears about their long-time political home confirmed.

Krauthammer — who, after completing medical school, began work as a psychiatrist in Boston —was a youthful recruit to the movement which, by 1979, was being described on the cover of Esquire magazine as “the most powerful new political force in America”.

In 1978, he accepted a post in the Carter administration at the National Institute of Mental Health. His articles for the New Republic magazine — the house journal of American liberalism but itself becoming a platform for many of those wishing to challenge its orthodoxies — caught the eye of Jimmy Carter’s vice-president, Walter Mondale, who recruited him as a speechwriter.

But Krauthammer, who viewed himself as a liberal Cold Warrior, shared the neoconservatives’ disdain for Carter’s dovishness. Despite working for Mondale, Krauthammer did not vote to re-elect the president in 1980.

In the pages of the New Republic, where he found a journalistic perch after Carter’s defeat, he became a trenchant advocate of Ronald Reagan’s vision of “peace through strength”.

He coined the term the “Reagan Doctrine” to decribe the president’s support for anti-Communist forces in Central America. Krauthammer’s backing for Mr Reagan’s “freedom fighters” in Nicaragua — the contras — proved especially unpopular among many of the New Republic readers. But it was cause which became a defining issue for fellow neoconservatives such as the writer Joshua Muravchik.

Krauthammer was also coming to recognise what Bell had earlier termed “the cultural contradictions of the welfare state”. “As a doctor,” Krauthammer argued, “I’d been trained in empirical evidence. If the treatment is killing your patients, you stop the treatment.”

Like Muravchik and Kristol’s son, William – the founder and editor of the “neocons’ bible”, the Weekly Standard — Krauthammer was an enthusiastic cheerleader for George W Bush’s “war on terror” and a fierce proponent of the Iraq war. He continued to defend Bush long after the former president had left office, comparing his stewardship of the struggle against “the fanatical ideology [of] radical Islam” to Harry Truman’s leadership in the early years of the Cold War.

The comparison was telling: for these younger neoconservatives, the president’s interventionist “freedom agenda” in the Middle East echoed Reagan’s muscular fight against Communist tyranny. Mr Bush’s opponents were thus simply the latest incarnation of those who had sought to accommodate, rather than defeat, the “Evil Empire” in the 1970s and 1980s.

Krauthammer also shared the neoconservatives’ dogged defence of Israel and fear of the existential threat posed to it by Iran. “Mourning dead Jews is easy,” he wrote on the 70th anniverary of the liberation of Auschwitz.

“And, forgive me, cheap. Want to truly honor the dead? Show solidarity with the living — Israel and its six million Jews.

Make ‘never again’ more than an empty phrase. It took Nazi Germany seven years to kill six million Jews. It would take a nuclear Iran one day.”

Krauthammer was too principled and decent to throw in his lot with Donald Trump, seeing him a phony who combined “supreme ignorance to supreme arrogance”. “I used to think Trump was an 11-year-old, an underdeveloped schoolyard bully,” he wrote in the summer of 2016.

“I was off by about 10 years. His needs are more primitive, an infantile hunger for approval and praise, a craving that can never be satisfied”.

In his distate for the president, Krauthammer was, once again, in step with the dominant strand of neoconservative thinking.

While many Republicans eventually fell in line behind Mr Trump, Jewish conservatives such as William Kristol; Muravchik; Washington Post columnist Jennifer Rubin; the foreign policy expert Max Boot; journalist and writer James Kirchick; and Robert Kagan, the historian and foreign policy commentator, were among his most vocal and prominent critics.

This opposition is ideological. Trump’s isolationist “America First” approach is as alien to neoconservatives today as was McGovern’s softer variant four decades ago.

But it is also a culturally conservative fear of the “mobocracy” and of what Boot termed the “ugly nativist populism” the president both represents and amplifies.

Krauthammer viewed politics as the “moat … beyond which lie the barbarians” and his conservatism was inseparable from the fact that he regarded the Holocaust as “an ineradicable element of my own Jewish consciousness”. It tempered “your optimism and your idealism,” he argued on one occasion.

Watching the political earthquake that was Trump’s election in 2016, Krauthammer immediately understood its significance.

“What this means ideologically is that the Republican party has become the populist party and the country is going to be without a classically conservative party,” he told television viewers.

For Krauthammer, history was “a battle of ideas”.

In its ongoing duel with Mr Trump, neoconservatism has lost one of its most impassioned and eloquent warriors.