Cut a deal, Mr. Prosecutor, and spare us and our city the further agony and humiliation of a racially divisive public trial of Marion Barry. That's the essence of the unsubtle, and unhelpful, public plea-bargaining argument being made by some of the mayor's allies and not a few seemingly self-appointed political spokesmen.

It's too late for that. Setting aside the questionable tactics implicit in this direct intrusion into the judicial process, Washington long since has passed the point of no return on the Barry affair. For months, if not years, the mayor's actions have brought shame to the city and left its residents racially polarized, its economy weakened and its government a shambles.

Now, as his own time of judgment approaches, not only Barry is on trial. Washington's judicial and political system, as well as its people, also are on trial. The test before them is to perform fairly and calmly and in a manner that reassures the city instead of tearing it apart.

In the current emotional environment, that's a formidable task. It's made more difficult because of the additional burden of having to contend with public figures trying to intervene in the case, treating it as if it were a legislative or political matter instead of a judicial one. Even if they are "people of good will . . . trying to come forward and see if they can't bring this case to an end," as Barry's defense attorney, R. Kenneth Mundy, calls them, their efforts only aggravate an increasingly tense situation.

Principal among those offering gratuitous and widely publicized advice about the Barry case is Jesse L. Jackson. While jury selection proceeds at a laborious pace, Jackson has been sounding off in media interviews about the strategy that Mundy and U.S. Attorney Jay B. Stephens should pursue. Jackson is pressuring both sides.

To Barry, and through the media, he says don't run again. Announce that you will not seek a fourth term as mayor. If Barry does so, Jackson tells The Washington Post, such a "candid declaration" would be "a major step toward further creating a climate for a settlement."

To the prosecutor, again through the media, Jackson says make a good plea-bargain offer to the defendant. If you do, Jackson suggested in a television interview, Barry would be likely to announce "that he would choose publicly not to run again."

Jackson went further in pressuring prosecutor Stephens. If Barry agrees not to run, Jackson told The Post rhetorically, "then the question really is: Why then prosecution and persecution?"

In thereby directly equating the prosecution's case against Barry with "persecution," Jackson gave fuel to those charging loudly that the mayor is a victim of racial conspiracy by whites out to bring down the black leader of the nation's capital. That kind of comment is about as helpful as throwing gasoline on a roaring fire.

Here's one Washingtonian who says let the judicial process proceed. If the principals involved strike a plea bargain, fine. If they don't, that's fine too. Either way, leave this to the judicial system, and let the public judge the results.

There is, in fact, a case to be made that Washington's long-term interests will be served best by having Barry's trial proceed to a verdict. Difficult and inflammatory as the trial almost certainly will be, and whatever the result, it will provide a documented record that could be useful in putting the case against the mayor into better perspective in years to come when passions have subsided.

To judge from the superheated rhetoric, especially over the electronic airwaves, the Barry case symbolizes naked racism and a vendetta by the "white establishment" and the "white press" against a major American black public figure.

But this case is no more about race than about the fate of one politician. It stands for something far more important. As I have noted here previously, it is essentially a case about deceit and betrayal of public trust.

The tragedy of Marion Barry is that he let down the citizens of a city that had been making steady progress in self-governance and was becoming a great world capital.

The claim by Barry's minions, and by the mayor himself, that he is a victim of racism is false. Barry is a victim of himself, and I believe that the vast majority of Washingtonians, black and white, understand that.