SEVERAL WEEK AGO, I found myself watching the Phil Donahue Show on the day that his guest was Rita Demure, the errant congressional wife, who appeared discreetly wrapped in black to chat up her Playboy photographs and her adventures in Sodom on the Potomac. After all I'd read about her, I was thorougly prepared to dislike her, and the fact that I was exhausted and she looked divine did not help her case. a

But by the end of that historic hour in which Rita found herself talking to her estranged husband on the air, I ended up sort of liking her. She is, no matter what else you think of her, something of a fighter and while she has riled up a number of congressional wives who say she's giving political life a bad name, that is not a criticism people can take terribly seriously. Rita Jenrette is not your typical congressional wife. She is first and foremost an attractive, flashy blond with a remarkable gift for candor. She had the bad fortune of being married to bed-hopping John Jenrette, and if she loved him at all, that couldn't have been too much fun. Then she posed for Playboy and wrote a quickie book about her experiences, and has in the process made some fast money. Virtue may be its own reward, but a girl's got to make a living.

But then Rita Jenrette showed up in Washington the other night at the White House correspondents' annual awards dinner, again dressed in demure black and catching the eye and attention of practically everyone there. There were, of course, a lot of much more famous people there and a lot of much more important people there, but Rita was a center of attraction, the woman who was photographed with both the editor and the president of U.S. News and World Report, just as if the three of them had no end of things in common to talk about. The other folks at the dinner may have had prestige, power and money, but Rita has the real coin of the realm: celebrity.

And she is riding it for all it's worth. For Rita Jenrette, just as for the Judith Exners, the Elizabeth Rays, the Paula Parkinsons, fame is instant and it doesn't last long, because it really isn't fame at all: it's notoriety. They aren't famous for doing something very smart, or even clever. They are famous for doing something risque or tacky and getting away with it. Willie Suttons of the bedroom.They are the logical byproduct of America's sexual romp, in which anything goes and everything gets discussed. If a congressman's wife talks about having sex on the steps of the Capitol we might wince collectively at the discomfort involved, but it shouldn't come as too much of a surprise.

And there's money in this notoriety: a book for Rita, Playboy pictures, and now a movie role; a book for Exner, nightclub acts for Ray and Fanne Foxe -- you do remember Fanne Foxe, don't you? -- memoirs in the works for Paula Parkinson. And if there's money, it means somebody's willing to pay to see them and pay to read what their ghostwriters say they have to say. Celebrity is a joint venture, involving a willing, hungry public. The ladies don't have much profound to say, but because they are notorious we listen. They'll do the talk shows and the talk show hosts, to a man, bend over backwards not to be judgmental. Phil Donohue, every talk show host's favorite role model, is nothing if not a gentleman when he is interviewing the latest notorious lady.

"Let me ask you this, Lady MacBeth, and I hope you won't think I'm being too personal, but you are here after all to tell us about yourself. When did you first sense things were not right with your husband's career? Be honest with us, we all understand the strains of public life."

Evil has always been more interesting than good, except when good comes in heroic proportions. We live in a time when there aren't many heroic politicians, generals or sports figures. Our literary heroes are not the writers who write great books but the ones who land huge paperback contracts. The ballplayers who stand out are the ones who negotiate enormous contracts -- no matter that they might be ruining the economics of the sport they are paid to play in the process. Lacking genuine heroes, we've gotten the next best thing: cheap-thrills people who can capture our attention. We might be astounded to see a Rita Jenrette at a White House correspondents dinner but she was a star there and even the powerful snickered and stared. They, too, need their celebrity fix, and if the object of their attention got that way because of what we might in a more judgmental age have called a hint of scandal, well, no matter.

You never know who is going to be notorious next.