WITH APPROPRIATE deliberation and dispatch, members of the Senate Ethics Committee have faced up to the unpleasant but essential task of passing judgment on a colleague convicted of serious crime--and they are unanimous in their recommendation that Harrison A. Williams Jr. of New Jersey be expelled unless his bribery-conspiracy conviction is overturned on appeal. This decision is both severe and generous, given the gravity of Mr. Williams' misconduct in public office and the fact that what the Senate ultimately decides need not await or be affected by disposition of his appeal in the court.

From the outset of their deliberations, the committee members' decision hinged not on the legal questions that were and are still before the courts, but on the question of whether the conduct of their colleague was consistent with a senator's sworn duty and responsibilities as set forth in the Standing Rules of the Senate. In May, after months of staff review, the committee took action that amounted to an internal version of an indictment; it then remained to decide whether punishment--ranging from reprimand to expulsion--was called for and if so, what it should be.

On this point, if not on the question of when the full Senate should act, the committee decision is firm: As Chairman Malcolm Wallop (R-Wyo.) stated, the committee found, "based on the evidence before it, that Sen. Williams's conduct was ethically repugnant to the point of warranting his expulsion from the United States Senate." Just as a jury earlier rejected the senator's version of events and concluded that he did try to exploit his office for personal gain, the committee reached a similar conclusion about his conduct as a member. And such behavior would constitute a violation of Senate rules and be ample cause for expulsion as is recommended.

The sooner the next vote, the better. It is awkward enough already for the Senate to be keeping in its number a member convicted of serious crime and found by a committee of his colleagues to have abused his office in the process. Barring some immediate, extraordinary turn of events, a vote is in order.