THE CASE of Sen. Harrison Williams involves two separate problems, and you need to understand the distinction between them. First, did the senator receive a fair trial last May on the charges of nine separate violations of federal law? A unanimous jury thought so and voted to convict him on all counts. That conviction is now under review by the trial judge (who is expected to rule this month) and then is subject to appeal through the federal court system right on up to the Supreme Court. Issues of entrapment, immunity for government witnesses and other due process questions will be considered in that forum.

An entirely different question is whether Mr. Williams should be expelled from the Senate for certain activity--some of it apart from the crimes for which he was convicted. That question must be decided by the Senate itself, which will determine whether his pattern of behavior as a whole justifies this severe penalty. The unanimous judgment of the Senate Select Committee on Ethics is that Sen. Williams' conduct was "ethically repugnant, and tends to bring the Senate into dishonor and disrepute." Expulsion was unanimously recommended. The committee stresses that its recommendation, like that which the Senate in turn will make, must be made independently of both the jury's verdict and any action that any court may take in the criminal case. Their position, in other words, is that even if Sen. Williams' conviction were ultimately reversed on due process grounds, there would still be ample reason for putting him out of the Senate, given his violations of the Senate's own rules.

What were these? Having concurred in the New York jury's verdict, the committee then cited seven specific violations of the Senate's code of ethics and made two additional charges. It concluded that he had tried to get money for a business enterprise in which he had a financial interest by promising to use his official position in the Senate to assist in obtaining government contracts. The committee found that in exchange for this loan, he promised to introduce legislation that would assist an alien in immigrating to the United States. It charged that he had circumvented the public financial disclosure requirements of the Senate rules, that he had improperly failed to report to law enforcement authorities an offer of a bribe and that he had lied to FBI investigators in the early stages of the Abscam investigation.

Having had a full trial on the question of violation of law, and having had a thorough hearing before the Senate ethics committee--during both of which procedures he was assisted by counsel, was able to present evidence and was given a chance to call and cross-examine witnesses--the senator now appears to believe that he is entitled to yet anotherfull-scale trial, this time before the whole Senate. Why should that be?

Rumors abound in this city that some new evidence has been found that will exculpate the senator. Last month, at the request of the leadership, the ethics committee re-examined the record, heard Sen. Williams once again and agreed to stand by its original report. Further lengthy procedures are not necessary. Senators can read the trial record and the well-documented 127-page report of the ethics committee. Sen. Williams, assisted by his colleague, Sen. Daniel Inouye, can present a defense, rebut committee charges and even offer new evidence to all his colleagues. But without further delay the Senate should vote. Its honor, not just that of the gentleman from New Jersey, is at stake.