Mort Sahl, the comic whose caustic and fearlessly observant routines about Cold War politics in the button-down 1950s transformed American comedy and paved the way for generations of acid-witted humorists, not least Jon Stewart and Bill Maher, died Oct. 26 at his home in Mill Valley, Calif. He was 94.

His friend Lucy Mercer confirmed the death but did not cite an immediate cause.

Before Mr. Sahl, wisecracks about government and Washington were little more than glib asides with no attempt at the jugular. For the most part, comedians avoided topics that might alienate escapist-minded radio, TV and nightclub audiences and stuck to safer material about mothers-in-law or nagging spouses.

By contrast, Mr. Sahl dove headfirst into the divisive politics and tumult of his time — from the nuclear arms race to segregation — with erudite outrage, a finely tuned sense of the absurd and a high tolerance for risk. Referring to his more genial comic forebear, Time magazine described him in a 1960 cover story as “Will Rogers with fangs.”

Mr. Sahl developed a trademark look — a V-neck sweater and loafers, befitting a graduate student — and he carried onstage the rolled-up newspapers whose headlines he had plundered for inspiration. Having honed his style in seedy San Francisco bars and coffeehouses, he riffed in knowing argot about presidential politics, Cold War paranoia, institutionalized religion and neurotic relationships between the sexes.

During the height of Sen. Joseph McCarthy’s anti-communist witch hunts, which ensnared numerous entertainment figures, among other targets, Mr. Sahl took the position that “McCarthy doesn’t question what you say as much as your right to say it.”

He painted President Dwight D. Eisenhower as a blandly avuncular, distracted, golf-obsessed leader. Amid the 1957 racial integration showdown in Little Rock, Mr. Sahl joked that Eisenhower considered walking a Black girl to school but could not decide “whether or not to use an overlapping grip.”

He mocked talk of the “missile gap” during the 1960 presidential campaign, wryly jesting, “Maybe the Russians will steal all our secrets, then they’ll be three years behind.” And he spoke facetiously in favor of capital punishment, observing, “You’ve got to execute people. How else are they gonna learn?”

With more sophistication than a string of staccato one-liners, his jokes formed a free-flowing narrative punctuated by references to political and diplomatic leaders including Secretary of State Christian A. Herter, Cold War hot spots such as Malta and Pakistan, and legislation such as the Taft-Hartley Act.

In one discursive story about Eisenhower’s travels abroad, Mr. Sahl said that White House press secretary James C. Hagerty grew testy when reporters asked when the president might visit Russia.

“Hagerty was quoted as saying, ‘Don’t ask me, I’m not God,’ ” Mr. Sahl said. “Somewhat out of proportion to the question.”

In “Seriously Funny,” a book about rebel comics of the 1950s and 1960s, Gerald Nachman explored the novelty of Mr. Sahl’s intellectual, explanatory style and his Ivy League wardrobe.

“Pre-Sahl was a time in which comedians, clad like bandleaders in spats and tuxes, announced themselves by their brash, anything-for-a-laugh, charred-earth policy and by-the-jokebook gags,” Nachman wrote. “Sahl challenged and changed all that simply by the comic device of being himself and speaking his mind onstage.”

At the end of his shows, Mr. Sahl would ask, “Is there anyone here I haven’t offended?”

Playboy magazine publisher Hugh Hefner became an admirer of Mr. Sahl’s humor and promoted him as an exemplar of cool sophistication. The comedian performed on Broadway and in Playboy Clubs, acted in films, recorded popular comedy albums and appeared on a bevy of late-night and other comedy shows.

He was regarded as a pathfinder for the more topical, personal or offbeat styles honed by Lenny Bruce, Bob Newhart, Mike Nichols, Dick Gregory, George Carlin, Joan Rivers and Mark Russell.

In 1954, a 19-year-old Woody Allen saw Mr. Sahl perform at a New York nightclub and for years mimicked his delivery style. “He was the best thing I ever saw,” Allen once said. “He was like Charlie Parker in jazz. . . . He totally restructured comedy.”

Behind Mr. Sahl’s humor lay a deep concern for American democracy, and his onstage probing was the antithesis of the cheap laugh. He sometimes warmed up crowds for his friend Dave Brubeck, but the jazz pianist complained that “he demands so much of an audience that it hasn’t the strength for anyone else.”

His high-minded material itself invited satire. In the early 1970s, Carlin portrayed a manic Mr. Sahl uncorking a ludicrous rant about the Arab League, student riots in Japan, Eisenhower watching a movie in Manila and the role of Asian religions in ecclesiastical history.

By then, Mr. Sahl’s career had fallen into decline, a development owed almost wholly to his nonstop ribbing of President John F. Kennedy and his obsession with his assassination in 1963.

Mr. Sahl had admired Kennedy and even contributed one-liners to his 1960 campaign speeches. But, fiercely independent and vowing to make any White House occupant the butt of his humor, he let loose when Kennedy won. He joked about Kennedy’s wealthy father influencing the election outcome (“You’re not allowed one more cent than you need to buy a landslide”), the Kennedy preoccupation with communist Cuba, and the new president’s rumored mafia connections.

He incurred the wrath of Kennedy intimates and said his livelihood was threatened. Many nightclubs, fearing tax audits, stopped booking him. Some liberals in his fan base, having grown accustomed to gibes about Eisenhower and Nixon, abandoned him.

Mr. Sahl plowed ahead and made an even more radical shift after the assassination.

Deeply shaken by the killing, he became convinced that the Warren Commission, which investigated the assassination, was a farce and that the CIA had participated in a plot to kill Kennedy. Onstage, Mr. Sahl read excerpts from the commission report that he considered full of comically tortured logic, and he rambled on about various conspiracies.

He journeyed to Louisiana, where the controversial New Orleans district attorney Jim Garrison deputized him to help investigate an alleged government coverup. Putting comedy aside, Mr. Sahl spent several years traveling the country interviewing witnesses and evaluating evidence.

Invitations to appear on TV shows and in clubs dried up. In his 1976 memoir, “Heartland,” Mr. Sahl wrote that his earnings fell from $1 million a year to “about nothing.” But he made a comeback after Watergate, when his searing skepticism and dark view of American leadership better matched the national mood.

“The harvest of what we found came out repeatedly afterward in Watergate, the Iran-contra affair, the whole idea of shadow government and of people who think they know better what’s good for Americans,” Mr. Sahl told the makers of a public television documentary about him in 1989.

He returned to nightclubs and had a one-man Broadway show in 1987. Mr. Sahl still impressed with his steady supply of zingers.

One of them involved his friend, former secretary of state Alexander Haig, and the U.S. embargo of Cuba. Mr. Sahl explained: “I was with him when he lit up a Havana cigar, and I asked him, ‘Isn’t that trading with the enemy?’ He told me, ‘I prefer to think of it as burning their crops to the ground.’ ”

Morton Lyon Sahl was born in Montreal to American parents on May 11, 1927. His father, Harry, a failed left-wing playwright from New York, ran a tobacco shop to support his family. The Sahls later settled in Los Angeles, and the elder Sahl became an FBI clerk.

According to Nachman, Harry Sahl cast a pall over his son’s view of the world. “It’s all fixed,” he would tell Mort, referring to show business. “They don’t want anything good.”

In high school, Mr. Sahl joined the ROTC, and by his own account became an expert marksman and “something of a martinet.” At 15, he enlisted in the Army by lying about his age. His mother found him two weeks later and ushered him home.

Undaunted, he joined the U.S. Army Air Forces after high school graduation and was sent to an outpost in Anchorage, where his contrarian spirit made an untimely emergence. He grew a beard and tried to turn a base newspaper, which he edited, into a muckraking journal. His efforts earned him ample KP duty before his discharge in 1947.

He graduated in 1950 from the University of Southern California. While doing odd jobs, he wrote a novel and a play that found no takers.

He followed a girlfriend to San Francisco, where in 1953 he began trying out comic material at a basement bar called the hungry i, a rendezvous for beatniks that charged a 25-cent entrance fee.

Mr. Sahl, who had been living in the back of a station wagon, said it took three months to get his first laugh. The winner was a Cold War joke about McCarthy’s anti-communist crusades: “Every time the Russians throw an American in jail, we put an American in jail to show them they can’t get away with it.”

His success at the hungry i led to more prominent engagements in Los Angeles, New York, Chicago, Las Vegas and Miami Beach. A heavy coffee drinker largely averse to alcohol and cigarettes, he led a busy life that took a toll on his private affairs.

All three of Mr. Sahl’s marriages — to Sue Babior, former Playboy centerfold China Lee and Kenslea Ann Motter — ended in divorce. His son with Lee, Mort Sahl Jr., died of a drug overdose in 1996. He had no immediate survivors.

Mr. Sahl performed well into his 80s, even after a mild stroke. He often made light of death, but with a sharp political eye. Referring to the Windy City’s reputation for electoral fraud, he once quipped: “I’ve arranged with my executor to be buried in Chicago. When I die, I want to still remain politically active.”