Another Reagan administration appointee has done the president a favor by declining to continue in his service. This time the departing official is Donald Devine, whose renomination for another statutory four-year term as head of the Office of Personnel Management was, by Mr. Devine's as well as by others' calculations, headed for rejection by the Republican-controlled Senate.

The decisive event, for a crucial number of members of the Senate Government Affairs Committee holding hearings on Mr. Devine's renomination, was testimony by another administration official, Loretta Cornelius, who has been acting as OPM's director since Mr. Devine's first term expired in March. Before he left office, Mr. Devine apparently made a secret delegation of his powes to the new position of executive assistant, which he then assumed. Mrs. Cornelius testified that she didn't know about the delegation until about a month later, but that Mr. Devine, fearful that the admission would damage his position with the Senate, asked her to say that she had known about the delegation all along.

Mr. Devine says that the delegation was legal -- the General Accounting Office disagrees -- and that he wasn't asking Mrs. Cornelius to lie outright, simply to construe her signing of various papers when she took office as implicit acknowledgment of the delegation. Most members of the committee apparently didn't need to learn any more about this tangled affair to conclude that renominating Mr. Devine was not in the best interests of the government.

Many committee members, perhaps a majority, were already deeply troubled by the inappropriate, if not illegal, way in which Mr. Devine and his close colleagues had politicized the national and regional operations of OPM -- the agency chaged with overice. Nor were members comforted by remembrances of Mr. Devine's needlessly disruptive way of carrying out administration policies even when they were sensible.

We have noted before that no OPM director charged with laying-off and downgrading many thousands of government workers or making other needed reforms can expect to win a popularity contest in this city. But, as other administration officials have learned by this time, most bureaucrats are capable, hard-working and used to adapting to changing political leadership. They simply don't take well to petty harassments or to having their integrity and ability repeatedly impugned.

Mr. Devine, of course, had his supporters, among them the editors of The Wall Street Journal. Just for the record we would like to correct a statement made in a recent Journal editorial that the "Washington Post editorially endorsed Mr. Devine." We've reviewed our editorials on the subject pretty carefully and can only conclude that so many harsh things have been written about Mr. Devine that merely to accuse him of "petulance," "inattention," "neglect" and "hostility" on the job may seem by comparison an endorsement. But it wasn't meant to be. We suspect our friends at The Wall Street Journal will not mind our clearing up this confusion, as they will doubtless be far more comfortable -- we both will be -- to find themselves on the familiar other side of the issue from us.