BECAUSE Marianne Mele Hall has been appointed by the president to be chairman of the Copyright Royalty Tribunal -- a regulatory agency whose members serve for fixed terms -- and has already been confirmed by the Senate, she cannot now be fired by the president or anyone else. That is a pity. She probably can't be impeached, either, for something she did before taking office that is neither a high crime nor a misdemeanor. But she could be urged to resign by the people who put her in the position in the first place. The scandal is that they have been silent about her participation in the publication of a book that contains really abhorrent racist material.

We are very mindful here of the freedom of expression and association that are always tested when people of loathesome belief heave into public view. It is an unfortunate fact that some Americans believe in white superiority and the "jungle freedoms" hogwash that appeared in the tome Mrs. Hall edited. There are also, as a bemused nation has been reminded lately, people who believe that handicapped children summoned their fate. Repugnant as these beliefs are, they must be tolerated in this country. The people who hold them are free to speak as they wish, to publish what they want and to try to persuade others of the soundness of their crackpot views.

What is incredible, though, is that anyone should believe that such people are qualified for high federal office. Theoretically, the Senate should have caught this nomination, but the fault is at the other end of Pennsylvania Avenue.

Mrs. Hall says that she disagreed with the racist sentiments expressed in the book that bears her name, that she tried to dissuade the principal author from expressing them and that her role in the publication was limited to editing the words of others. Yet, until this controversy arose, she did not dissociate herself from the book. In fact, she listed herself as a "coauthor" on a Senate questionnaire required of nominees.

To its shame, the White House has not responded to the revelations in this book. Did the administration know about the views expressed in it? Do the president's personnel people agree with these views? Or does the White House, increasingly susceptible to these controversial appointments, simply find such opinions unimportant in evaluating potential nominees?

Members of the Senate Judiciary Committee have been embarrassed by this fiasco, and it is this committee that soon will review more than 100 of the president's nominees for lifetime federal judgeships. The administration owes it an explanation of how these outrageous mistakes have been made -- and it owes everyone a statement dissociating itself from the views in the book that bears Mrs. Hall's name.