SO much is being lost in this Iran-contra affair: There's the decline in President Reagan's credibility and the weakening of his presidency because of his forced preoccupation with this problem. Then, above all, there's the loss to all Americans when its government is impaired. But now it is becoming clear that American journalism is also suffering from its handling of the story. The credibility of both daily newspapers and television is down, according to a recent Gallup poll. Andrew Kohut, Gallup president, attributes this falloff in public confidence thus: ``First, news organizations are reporting on a story that many Americans find deeply disturbing; second, the public feels the story is being overreported; third, a significant backlash against press coverage of this story has developed among conservatives.''
Yet, from within the Washington Beltway, the media continue to keep the controversial story not only alive but also on the front pages or in the lead positions on TV news. The search for new ``revelations'' goes on. And, of course, the several official scrutinies under way into the affair are feeding daily information and articles.
This diligent reporting of the Iran story can, indeed, be called ``responsible journalism.'' After all, some laws may have been broken, and the President's judgment - if not his integrity - has been put in question. So the public's ``need to know'' is very much involved.
But it can also be argued that this Iran story is being ``driven'' to some extent artificially. New York Times columnist Tom Wicker, who believes firmly in the legitimacy of keeping the press coverage at white heat, concedes that the matter has become very ``partisan.'' ``Protest as they might,'' he writes, ``Democrats nevertheless see the arms scandal as both a political break for their party and a well-earned comeuppance for the casual Reagan style of `big-picture' governing, with little attention paid to details.''
Some of this same partisan attitude has helped to whip up media enthusiasm for the story. But - beyond that - there has to be some of this being said (or implied) by top editors to their staffs: ``Hey, get in and dig. This could be another Watergate. There's a Pulitzer Prize in them thar hills.''
Actually, that's nothing but good, aggressive journalism - up to a point. But one suspects that the inside-the-Beltway pursuit of the story has, at least at times, gone beyond that point - where the story is being driven by something more than responsible journalism.
When are the media merely responding professionally to the story and when are they, artificially, adding to the size of the story for their own self-interest? When are the media merely covering the story about power and those who handle power in this city and when are they imposing their own power? These are questions that can at least be asked.
Gallup also reports that its findings show that few people follow the arms scandal ``very closely'' - just 20 percent. This is to be compared with the 80 percent who followed the aftermath of the explosion of the space shuttle Challenger ``very closely'' and 46 percent the Chernobyl nuclear accident. Nearly 50 percent of the viewers say they follow the Iran-contra story ``fairly closely.'' And certainly enough readers and viewers are aware of the story to provide the widespread perception, found by Gallup, that public confidence in the media has taken a decided dip.
Won't these findings cause the media to take a sober look at their coverage? Perhaps. But within the Beltway, a parochial view tends to discredit such surveys. It's a bit like when the Washington Redskins are playing football here. The city stops, everyone hanging on every play. But it's more than that. There is a general assumption that everyone everywhere in the country is wrapped up in how the Redskins are faring. The truth is, of course, that other cities and areas have their own teams - and usually could not care less whether the Skins win or lose.
Washington is, for the most part, a partisan political city - very Democratic and very liberal. This includes the suburbs, certainly the Maryland suburbs. So this Iran story, with its prospect of wrecking the GOP Reagan administration, ``plays'' well here.
Thus, it would be surprising if the Washington Post were losing any subscribers as the result of its strong coverage of the affair. But other media might well note Gallup's finding. For example, the believability rating of CBS anchorman Dan Rather has dropped to 69 percent - from 81 percent in 1985. And the believability rating of the other anchors, NBC's Tom Brokaw and ABC's Peter Jennings, is also down.
Godfrey Sperling Jr. is the Monitor's senior Washington columnist.