As long as I’ve lived in America I’ve enjoyed the comic ritual known as the “hunt for the smoking gun,” a process by which our official press tries to inoculate itself and its readers against political and economic realities.

The big smoking-gun question back in 1973 and 1974 concerned Richard Nixon. Back and forth the ponderous debate raged in editorial columns and news stories: Was this or that disclosure a “smoking gun”? Fairly early in the game, it was clear to about 95 percent of the population that Nixon was a liar, a crook and guilty as charged. But the committee rooms on Capitol Hill and the Sunday talk shows were still filled with people holding up guns with smoke pouring from the barrel telling one another solemnly that no, the appearance of smoke and stench of recently detonated cordite notwithstanding, this was not yet the absolute, definitive smoking gun.

So it became clear that the great smoking-gun hunt was really about timing, about gauging the correct temperature of the political waters. Then suddenly, in the late summer of 1974, that impalpable entity known as elite sentiment sensed that the scandal was becoming subversive of public order, that it was time to throw Nixon overboard and move on. A “new” tape–though hundreds of others had already made Nixon’s guilt plain–was swiftly identified as “the smoking gun” and presto! Nixon was on the next plane to California.

In the mid-1970s post-Watergate euphoria, smoking guns were in fashion. In the Church Intelligence Committee hearings they actually held up a gun to demonstrate the profuse, well-documented efforts of the CIA to assassinate Fidel Castro. In other hearing rooms witnesses testified that multinational corporations offered bribes to win business.

Appropriately enough, it was a newspaper publisher who stepped forward in the late fall of 1974 to announce that the smoking-gun show was now officially closed. At the annual meeting of the Magazine Publishers Association, Katharine Graham, boss of the Washington Post Company, sternly cautioned her fellow czars of the communication industry (many of them bribed to endorse Nixon in 1972 by his gift of the monopoly license to print money, known as Joint Operating Agreements).

“The press these days,” Mrs. Graham declared, “should…be rather careful about its role. We may have acquired some tendencies about over-involvement that we had better overcome. We had better not yield to the temptation to go on refighting the next [sic] war and see conspiracy and cover-up where they do not exist.”

By 1975 smoking guns were a thing of the past. The coup de grâce was PBS’s MacNeil/Lehrer Report, which started in October 1975, dedicated to the proposition that there are two sides to every question, and reality is not an exciting affair of smoking guns, crooked businessmen and lying politicians but a dull continuum in which all involved are struggling disinterestedly for the public weal. In this new, prudent post-Watergate era, which has stretched through to the present day, there were no smoking guns. It wasn’t long before those documented attempts to assassinate Castro became “alleged attempts” or, the final fate of many a smoking gun, “an old story.”

CIA involvement in opium smuggling in Southeast Asia? There were smoking guns aplenty. In a 1987 Frontline documentary, Tony Po gave an on-camera interview confirming that in his capacity as a CIA officer he had given the mercenary general Vang Pao an airplane with which to transport heroin, because Vang Pao’s use of the CIA air fleet was proving embarrassing. “We painted it nice and fancy,” Po reminisced jovially. These days, the CIA’s complicity in shuttling heroin that came home to America in body bags from Vietnam has retreated to the decorous status of being an “allegation” and, simultaneously, “an old story.”

Iran/contra, cocaine-for-arms shuttles supervised by the CIA? More smoking guns in every filing cabinet, and all over Oliver North’s diary. Ten years later Gary Webb of the San Jose Mercury News fished out further smoking guns and was rewarded by having his career destroyed by the Washington Post, New York Times and Los Angeles Times. When the hubbub died down, the CIA’s Inspector General admitted in his reports that yes, there were smoking guns, but the press only read the CIA’s press releases, which strenuously maintained the opposite.

I think it was in the Reagan era that the smoking-gun lobby got decisively routed. Month after month the official press would write respectfully about Reagan’s press conferences as though the President was a competent captain of the national ship instead of a fogged-up fantasist.

Another coup de grâce came in Clinton time, when the hunt for smoking guns became either incomprehensible (Jeff Gerth’s stories on Whitewater) or tacky (Clinton’s physical interactions with Monica Lewinsky). Special Prosecutor Ken Starr cried out that yes, he had the smoking gun. The people looked at the stained dress he proudly flourished and said, If that’s a smoking gun, we’re not interested.

There are enough smoking guns in the Iraq saga to stock a whole new national museum. It’s what makes the current muttering in the official press about the Downing Street memo so comical, with all the huff and puff about the “blogosphere” and how yes, this is an old story, and an “uncorroborated” one (like all those stories from detainees about desecration of the Koran).

What’s striking to me is how querulous and old-fashioned those “old story” put-downs about the Downing Street memo by Todd Purdum and others in the New York Times, or Howard Kurtz and Dana Milbank in the Washington Post, sound–rather like very old uncles wagging their fingers at naughty little children and admonishing them to stay quiet until all the facts are in.

But the facts are in, and the naughty children have the public megaphones. The rules of the game are changing. History is one big smoking gun and the function of the official press is to say this isn’t so. So what happens when fewer and fewer people take the official press seriously, or even read it?