Journalists - or just a herd of sheep in hacks' hats?

When Robert Redford and Dustin Hoffman endowed Bob Woodward and Carl Bernstein with cinematic life in All the President's Men , they affirmed a cherished self-conception of the Washington press corps.

Reporters on the Beltway beat were sexily serious and seriously sexy. Uncovering the Watergate scandal, the press nailed the President. Now, the mystique of smoke-wreathed newsrooms finds fresh confirmation in George Clooney's second directorial feature, Good Night, and Good Luck : a tribute to the venerable radio and television personality Edward R. Murrow.

For a generation that knows Clooney from the television show ER but for whom E. R. Murrow is unfamiliar, Clooney's film reconstructs a mythic moment from TV's infancy: when the CBS presenter punctured the sagging credibility of Senator Joseph McCarthy. Any resemblance between the present and the 1950s - when swaggering braggarts trampled civil liberties largely unchallenged by a pusillanimous press - is quite accidental, Clooney insists. But even those who concur that Good Night is not a contemporary intervention would find it hard to deny that a certain nostalgia pervades its depiction of a bygone era of reportorial intrepidity. A similar wistfulness suffuses Donald Ritchie's history of the Washington press corps.

Ritchie's canvas is expansive. Chronologically, he progresses from the interwar explosion of federal activity under Franklin D. Roosevelt to today's proliferation of electronic media. Some topical chapters chart the fortunes of particular media, as technologies and outlets ceaselessly rise and decline, or mutate and merge. Others document singular moments in media and political history such as the slaying of McCarthy and unplugging of Watergate.

Ritchie is an especially astute observer of how the Washington press corps cultivated its own practices. Its exclusive institutions, the Gridiron and the National Press Club, long debarred women and African-Americans, while segregated press galleries gave physical expression to hierarchies of prestige among the media. Television crews at first struggled to gain elbow room, just as radio reporters had earlier battled against print media for access to news. As in other spheres, the formal abandonment of segregation did not automatically bestow access to professional privilege. For women and "minority" journalists gaining space on the front page, or on-camera airtime, has proven more difficult than getting served at the Gridiron.

Ritchie writes engagingly about the foibles of two species with whom he is well acquainted through years of service in the Senate Historical Office: politicians and the press. His approach is less argumentative than anecdotal. He offers a bustling narrative, conveying a sense of perpetual motion wrought by revolutions in technology, shifts in fashion and reversals of fortune. Other than the incredible longevity of some pivotal columnists, editors and publishers, there are few fixed points in the saga.

Rather, a succession of monstrously inflated egos strut and fret through the history: characters swollen by excessive self-regard, yet querulously insecure; careers buoyed and ruined by alcohol.

However lively its brushwork, a work of portraiture runs the risk of leaving interpretation sketchy. Ritchie offers a number of recurrent motifs rather than a central thesis. Certain professional tensions and pendulum swings intrigue him: objectivity versus opinion; investigation versus corroboration; competition versus collaboration. For all the rivalry in newsrooms and between news media, Ritchie draws repeated attention to curiously herd-like tendencies. Other than being clustered in a capital, what constitutes a collection of reporters as a "corps" is their behaviour as a pack: or, as Ritchie inclines to see it, a herd of sheep in wolves' clothing - eager for scoops yet anxious about leading where others fear to tread.

Chronicling a profession driven by ever more compressed news cycles, Ritchie's historical sense is more cyclical than teleological. An upbeat epilogue insists that 9/11 restored professional purpose and vocational seriousness to the US press - squandered in the sensation-seeking Clinton years, and in danger of dissipating in the fetid blogosphere. But this chipper conclusion fails to arrest a sense of tailspin. It remains clear that in Ritchie's book reporters who court unpopularity, speaking truth unto power, deserve credit denied those whose chief interest lies in sniffing out sleaze. No matter how vociferously Matt Drudge may cast himself as a latter-day Thomas Paine, it is all too apparent that truth seekers are losing ground to dirt dishers.

Susan Carruthers is associate professor of history, Rutgers University, New Jersey, US.