The American humorist PJ O’Rourke, who has died aged 74 of lung cancer, was a writer of sharp wit that ranged from dry to lusciously over the top, but was always leavened by a measure of self deprecation that stopped it from being cruel or harsh. In the political satire that dominated his later writing, he became that rarest of things, a funny conservative.

His political writing was based on his early change of tack from 1960s lefty to what he could call the libertarian right, libertarian being the escape hatch for those trapped within the Republican party. His changing stance mirrored the course of his career, from the satire of the National Lampoon and hipness of Rolling Stone to more earnest outlets such as the Atlantic Monthly and the rightwing Cato Institute.

He had been instrumental in making the Atlantic Monthly Press a success; its editor Morgan Entrekin called him “one of the major voices of his generation”.

The recurrent theme in his writing was his place in his generation – the baby boomers. “My generation spoiled everything for you,” he told younger readers. “It has always been the prerogative of young people to look and act weird and shock grownups. But my generation exhausted the earth’s resources of the weird … all you had left was to tattoo your faces and pierce your tongues. Ouch. That must have hurt. I apologise.”

He was born in Toledo, Ohio, to Delfine (nee Loy), a housewife and later a school administrator, and Clifford O’Rourke, a car salesman. He went to Miami University in Oxford, Ohio – “the one where you can’t major in windsurfing” – and took a master’s in English (1970) at Johns Hopkins University, Baltimore, where he began writing for a local underground paper, Harry, and the Rip-Off Review of Western Culture, which got him a gig with the National Lampoon magazine in 1973.

He made his mark quickly, working on the stage show Lemmings, which made stars of John Belushi, Chevy Chase and Christopher Guest, and co-writing with the Lampoon founder Doug Kenney The National Lampoon High School Yearbook, based on a piece by Michael O’Donoghue. There was a strong Irish-American wise-guys at the back of the class vibe at the Lampoon.

Kenney also hailed from Ohio, but had attended a private school; the record of the fictional class of 1964 at a high school in Dacron (the name a cross between Ohio cities Dayton and Akron, but also a popular brand of cheap polyester cloth) was based squarely on O’Rourke’s days at Toledo’s DeVilbiss high. The yearbook itself was purportedly the property of one Larry Kroger, who would reappear in 1978 as the naive protagonist of the film National Lampoon’s Animal House.

By the time Animal House became a hit, O’Rourke was the editor-in-chief of the Lampoon, charged with “the Squaresville task of making the magazine show a profit”. In the 2018 biopic of Kenney, A Futile and Stupid Gesture, O’Rourke is portrayed in just that light – but his empathy with squares was crucial to the yearbook’s success.

Now he found himself out of place in a “clubby and snitty” atmosphere which remained as the creative core of the Lampoon moved on to Hollywood and Saturday Night Live. He turned the magazine, according to one critic, into “comedy you can jack off to”.

In 1981 he went freelance, writing for the top-payers such as Vanity Fair and Playboy. His key Lampoon essay “How To Drive Fast on Drugs While Getting Your Wing-Wang Squeezed and Not Spill Your Drink”, was reprinted in his first book, Republican Party Reptile (1987), a homage to Hunter Thompson, the chief exponent of gonzo journalism, that saw him appointed “foreign desk chief” at Rolling Stone, the ultimate hip boomer journal.

His writing moved from social satire to politics and he reported from war zones, where his knack for satirising the absurd found its true metier. His 1988 collection, Holidays in Hell, is perhaps the best of his 20 books. He became a celebrity, without slowing down in the least, but as I can attest after surviving a London evening with him and my then ABC television colleague Charles Glass, O’Rourke was one of those rare people who was nicer in private, going beyond his public affability, which often surprised those expecting combative wit.

In 1991 O’Rourke interviewed Bill Clinton, along with his Rolling Stone colleagues Thompson and William Greider, and its publisher, Jann Wenner. He quickly slid Clinton into identity politics via the Lampoon yearbook template. Clinton’s favourite Beatle was Paul McCartney: Clinton was the “band geek” who paid attention in class.

For a short time O’Rourke held down the right side of Point/Counterpoint on CBS’s flagship news show 60 Minutes, opposite the equally funny and acerbic Molly Ivins, but they were too brilliant a mix to last on network TV. As he once wrote, “no humorist is under any obligation to provide answers”.

That voice could lose its affability when writing for the Cato Institute, but the new millennium presented new problems, which his work for the Atlantic laid out clearly. A 2004 essay on listening to the radio host Rush Limbaugh shouting to his echo chamber of “ditto heads” led him to search for a leftwing equivalent, but when he could not find one he wound up blaming the entire media landscape. He complained in another essay you could not tell the “liberals who once led Vietnam protests in clown pants from the car ads”, ironically putting his young self and his father into the same boat.

His libertarian conservatism reached its apotheosis with Donald Trump’s taking over the Republican party, reflected in his 2016 book of election coverage How the Hell Did This Happen? He endorsed Hillary Clinton, because “she’s wrong about absolutely everything, but she’s wrong within normal parameters”. Although he claimed in 1992 he had “given up” the 60s, Trump was exactly the sort of spoiled preppy boomer O’Rourke could despise. But he might have looked back to his childhood, and Walt Kelly’s comic strip Pogo. It was Pogo who said: “We have met the enemy and he is us.”

In 1990 O’Rourke married Amy Lumet, daughter of the film director Sidney and granddaughter of the entertainer Lena Horne.

They divorced three years later, and in 1995 he married Tina Mallon. She and their children, Olivia, Clifford and Elizabeth, survive him.