Warren Hinckle, the flamboyant editor who made Ramparts magazine a powerful national voice for the radical left in the 1960s and later, by championing the work of Hunter S. Thompson, helped introduce the no-holds-barred reporting style known as gonzo journalism, died on Thursday in San Francisco. He was 77.

The cause was complications of pneumonia, his daughter Pia Hinckle said.

Ramparts was a small-circulation quarterly for liberal Roman Catholics when Mr. Hinckle began writing for and promoting it in the early 1960s. A born provocateur with a keen sense of public relations, he took over as the executive editor in 1964 and immediately set about transforming Ramparts from a sleepy intellectual journal to a slickly produced, crusading political magazine that galvanized the American left.

With cover art and eye-catching headlines reminiscent of mainstream magazines like Esquire, Ramparts aimed to deliver “a bomb in every issue,” as Time magazine once put it. It looked at Cardinal Francis Spellman’s involvement in promoting American involvement in Vietnam and the Central Intelligence Agency’s financing of a wide variety of cultural organizations.

It published Che Guevara’s diaries, with a long introduction by Fidel Castro; Eldridge Cleaver’s letters from prison; and some of the wilder conspiracy theories surrounding the Kennedy assassination. The magazine’s photo essay in January 1967 showing the injuries inflicted on Vietnamese children by American bombs helped persuade the Rev. Dr. Martin Luther King Jr. to take a public stand against the war.