Whatever the truth turns out to be about the explosive new scandal rocking the White House -- whether or not it proves to be the undoing of President Clinton -- the news media are sure to moralize about the arrogance of power. But some introspection would be fitting.The adrenaline rush of the national media was evident on the afternoon of Jan. 21 as TV network anchors breathlessly broke into regular programming to report that the president was in big trouble -- so big that Al Gore might soon be selecting the decor for the Oval Office.From Havana, Tom Brokaw anchored an impromptu NBC News Special Report titled "Investigating the President." From Washington, amid fast-breaking news of alleged efforts to cover up an affair between Clinton and a White House intern, correspondents hinted that the end of Clinton's presidency might be near.Minutes later, on ABC, Peter Jennings and Cokie Roberts spoke in similar terms. Then, Jennings turned to former White House official George Stephanopoulos -- currently an ABC "news analyst" -- whose loyalty to the truth seemed as murky as ever.The ground was shifting as they spoke. With Clinton's popularity high in the polls since his re-election, many news outlets were telling us that the country cared little about Clinton's sexual activities. Now, with jolting talk of perjury in the air, the tune has changed in a hurry.The national press corps is good at changing its tune, of course. During much of this decade, many journalists have seemed thrilled to comment on Bill Clinton's successful emulation of John F. Kennedy. Few suggested that JFK, who was sexually out of control in the White House, might be a bad role model for a president.In fact, some journalists suggested the opposite, as when Joe Klein appeared on the CBS program "Face the Nation" in May 1994 and declared: "In the 20th century, having an interesting sexual history is a leading indicator of success in the presidency."Klein, a staff writer for Newsweek at the time, warned that "we're reaching the point where we're going to wind up with government by goody-goodies." He voiced fear that the only officeholders left would be those "who have done nothing in their life except walk the straight and narrow, who have no creative thoughts." And he fretted aloud: "Have we created an atmosphere where ... no one with any interesting aspects of their past is going to want to get involved in politics?"The unstated assumption of many politicians -- and journalists -- is that whatever works is appropriate. That's what Joe Klein went on to personally demonstrate in 1996, when he lied for months on end while claiming not to be Anonymous, the author of the best-selling political novel "Primary Colors."My point is not to moralize against adultery or deception. But do we really believe that lying can be so easily compartmentalized -- that someone who is in the habit of mouthing untruths in one realm of life is likely to have a commitment to honesty in another?Dissembling tends to be habit-forming. And it easily becomes a slippery slope.Whatever works. It's a dismal "principle," for politicians and journalists alike.Naturally, it never hurts to advocate the abstract idea of honesty. It's only in the non-abstract real world that duplicity offers obvious advantages. In the words of the ancient Roman poet Juvenal: "Honesty is praised and starves."Those who don't find honesty compelling on ethical grounds might want to consider its distinct practical virtues. After all, in the long run, a big problem with telling lies is that it's so difficult to keep track of them.Top journalists might discover that if they were less accepting of the lies routinely told by official Washington, they would end up telling fewer of their own.