WASHINGTON. — VERY FEW FANS of Martin Luther King ever cheered at a Ronald Reagan rally, and until recently, very few fans of either ever heard of Milli Vanilli. In fact, it is a safe assumption that a week ago hardly any reader of this page knew that Milli is not a she, but an it -- an act, a pop-singing duo.
Clearly, forcing all three of these celebrated entities into the same newspaper column is an unnatural act. Yet here they are, because right now all three are in the news for essentially the same reason.
It's not that King, like Mr. Reagan, has published his autobiography, or that Milli Vanilli, like King, omitted some footnotes in a doctoral dissertation. Nor is it, as you might suspect, that Mr. Reagan, like Milli Vanilli, merely lip-synced the words for which he won the grand prize.
It is that differing degrees of fraud helped all three to fame. True, this is hardly a stop-press bulletin in Mr. Reagan's case, since he was both actor and politician. But never has he been so obvious about it as in his new book, ''Ronald Reagan: An American Life.''
He doesn't use the word ''fraud,'' of course, but he passes off his book as an autobiography, which implies (a) that he wrote it, and (b) that it tells all about his life.
He did not, and it does not. His reminiscences are its backbone, but it was written by Robert Lindsey. Ghosts are normal in public life, even these days, for ''auto'' biographies. As to content, the Reagan book is most interesting for what it does not tell.
It does not even mention, for example, Sam Pierce, the HUD secretary whom the president once mistook for a visiting mayor. It does not even mention Mr. Pierce's HUD, site of history's most expensive government scandal until it was overtaken by the savings & loan mess.
It does not mention Jim Watt, the Interior secretary who joyfully and with Reagan backing tried to reverse the environmental controls of the previous decade. It does not even mention Interior. Nor does it mention Anne Gorsuch, the Environmental Protection Agency administrator who was Mr. Watt's protege, and like him became an embarrassment to the administration. It does not mention EPA, or the word ''environment.''
But from these omissions one should not conclude that Mr. Reagan avoids every embarrassing person and scandal. In his way, he deals with Iran-contra:
He says of Ollie North, ''I knew little about him personally and never saw very much of him . . . .'' He explains, sort of, that he never approved swapping arms for hostages because the deal was that we would send the arms to Israel, which in turn would ship them to Iran.
He points gently at his pal, then-CIA director Bill Casey. Conveniently, Casey is dead. Mr. Reagan admits that investigation showed that under Casey, the agency ''did a number of things that were improper.'' We may never know the truth, he says, but ''respected neurosurgeons'' have told him that Casey's brain tumor may have ''affected his behavior and judgment . . . ''
Don't get the wrong impression: Mr. Reagan says that because he was president, he himself was ''ultimately responsible.'' But -- the inevitable but -- he was busy with other weighty business. ''A president simply cannot monitor the day-to-day conduct of all his subordinates . . . Unfortunately, there will occasionally be transgressions . . . ''
A little earlier, the hard-working president recalled that ''the days I liked best were those Fridays when I could break away a little early, about 3 or 3.30, and take off for Camp David.''
There is nothing in the 748-page book that will enlighten anybody who followed the Reagan presidency. It is an anthology of all the feel-good feature stories you ever read about his Tom Sawyer boyhood, his Win-one-for-the-Gipper movie days and his morning-again-in-America presidency. He did not intend it to be revelatory, but in its way it is.
So is the news that as a Ph.D. candidate, Martin Luther King used copious quotes and ideas of others without proper attribution. This tarnishes the ''Dr. King'' salutation used by his admirers, and encourages his enemies to try again, vainly, to tarnish his work.
Yet a bigger fuss is raised over disclosure that Milli Vanilli -- two young men whose name is on a hit record titled ''Girl You Know It's True'' -- didn't actually sing the song at all. It was dubbed by not two, but three other guys.
There are standards, you see -- standards for pop stars, for movement heroes, and for presidents. They're just higher for some celebrities than for others.