LEON JAWORSKI has agreed to serve as chief House investigator of the Korean lobbying scandals, and this time around you would expect not to hear quite so many charges that he is likely to "fix" the case he is being called in to investigate. That was the suspicion - and the cry - back in 1973 when Mr. Jaworksi succeeded Archibald Cox as Watergate Special Prosecutor. Both Mr. Jaworski's close association with the Texas - establishment politics of Lyndon B. Johnson and his willingness to take the jobat all in the aftermath of the firing of Mr. Cox contributed to the tell - me - another skepticism with which the news of his appointment was greeted. Why, after all, would a President who had already gave every sign of trying to thwart the investigation appoint everyone with whom he did not have a secret understanding or whom he did not control? No one has ever answered that question very well. The only thing that cna be said with certainty is that Leon Jaworski was Richard Nixon's biggest mistake.

A number of people have forgotten that fact or tend to overlook it in their displeasure that Mr. Nixon is still at large. And other reject it altogether, arguing that Mr. Jaworski himself was some kind of double agent and, in effect, the former President's saving friend. This school holds that prosecutor Jaworski was derelict in falling to press for a criminal indictment of Mr. Nixon and in acquiescing in President Ford's pardon - if not actually helping to engineer it. The case for a criminal indictment, where not merely a matter of bloodthirstiness, usually rests on 1) the idea that a prosecution was required on grounds of simple justice and 2) the assumption that there was a crucial, yet elusive, set of facts called the "truth," which would have been made available to the public in a criminal trial, but which instead were covered up for all time.

We think these views wildly overestimate the scope and range of any new material that might have come out in such a trial. And we think they equally underestimate, first, what is already known and, second, the tremendous legal obstacles in the way of any indictment. We also think that while Mr. Jaworski can be falted for some aspects of some of his choices along the way, the principal fact about his tenure as special prosecutor is simply this: Against overwhelming adds and with great cussedness, craft and skill, he made the case that drove Richard Nixon from office.

Nevertheless, in our view, the suspicion of Mr. Jaworski that some people are already expressing can't hurt and may possibly even help. For all we know it may aspire him, as such skepticism has in the past, to show people that he isn't kidding. The investigation he is taking over is shambles. A great deal more needs to be clarified concerning the conditions under which Mr. Jaworski will work. And the politics of the House in his affair are, in many respects, complicated beyond anything Mr. Jaworski ever encountered in Nixon investigation. There are, as well, people who argue that a special prosecution should be undertaken and that the House so - called ethics committee should be taken off the case altogether. We may be wrong, but it doesn't seem to us that Leon Jaworski would come out of public retirement to invite further allegations of a high - level cop - out, or unfavorable observations from the right about how harshly he treated a Republican President in comparison with his treatment of Democratic congressmen. We don't think the days ahead look awfully good, in other words, for those legistors who were up to their necks in Korean boodle.