A SURVEY made in 1985 by the National Institute on Drug Abuse concluded that 62 million Americans had tried marijuana at least once. Recent polls by Newsweek and USA Today found that Americans, by a vast majority, do not consider earlier use of marijuana as a disqualification for public office, including the presidency. So why was the Supreme Court nomination of Judge Douglas Ginsburg, who had already run into trouble on other counts, yanked so precipitously after the revelation of his use of marijuana as a student and professor? And why do Democratic candidates Albert Gore and Bruce Babbitt, on the other hand, seem to be riding out their disclosures of having tried marijuana as young men? To a student of the impact of television on society, the lesson seems to be this:
The iron law of politics in the media age is that you must live by the image you have created for yourself. Americans have come a long way in tolerance of departure from accepted norms since the day when divorce could be a barrier to election. But there is less tolerance for departure from your own portrait of yourself. The issue goes beyond perception of hypocrisy to an unsettling sense of vanishing identity.
Thus, Gary Hart's trouble was not so much his extramarital affairs as the violation of his proclaimed image of good family man. And Sen. Joseph Biden's problem was not so much his borrowing of speech lines and the enhancing of his r'esum'e as that these things violated the image of candor and breezy spontaneity that he had fashioned for himself. President Reagan, who had already disillusioned many Americans by violating his antiterrorist identity with the Iranian arms deal, seemed in danger, in his first defense of Judge Ginsburg, of destroying his antidrug persona.
The moral absolutist who associated himself with his wife's slogan, ``Just say no,'' and with drug testing for federal workers risked becoming a national joke when he invoked compassion for Mr. Ginsburg and asked, ``How many of us would like to have everything we did when we were younger put on the books?''
Involved in this is more than rhetoric coming back to haunt you or being ``hoist by your own petard.'' We are in a time of great public uneasiness about our public servants, a distrust of video image, and a search for something vaguely defined as true character. Who invents an identity will have to live by that identity, or take the consequences.
Daniel Schorr is senior news analyst with National Public Radio. In 1948 he reported from the Netherlands for the Monitor.