Forget the bravado, the insistent optimism, the determination to see things through. Marion Barry, whose trial on drug and perjury charges begins tomorrow, is a desperate man.

The evidence is in his stark revelation that he is no longer counting on facts, evidence or even the celebrated courtroom legerdemain of defense attorney Kenneth Mundy to beat the charges against him. He's hoping instead that at least one member of the jury will ignore whatever evidence the prosecution is able to put on and vote to acquit him. He is pinning his hopes not on the facts but on the prospect of a hung jury.

"I think the prosecutors know that in this town, all it takes is one juror saying 'I'm not going to convict Marion Barry. I don't care what you say,' " the mayor told Washington Post reporters in a truly astounding interview in which he also accused the government of trying to kill him.

He admitted that he had used cocaine the night of his arrest at the Vista Hotel -- one of the charges against him. The admission also cast doubt on his earlier denial that he had ever used illegal drugs -- the basis of the perjury count. He acknowledged the likelihood that even those sympathetic to him will believe that he has a history of drug abuse.

"I think if you talk to most Washingtonians -- even my supporters ... they may think that I may have done that {used cocaine}," he said. "So if {his erstwhile associates on the prosecution's witness list} testify that I'd used cocaine with them before, that's not damaging. People already think that."

If he admits some of the charges and expects jurors to believe many of the others, how can he expect to be acquitted?

The answer, in a word, is race. Barry begins with the knowledge that virtually all black Americans believe themselves to have been treated unfairly by whites at some time in their lives. His strategy is to paint himself as a sort of black Everyman, with the hope that at least one member of what will surely be a majority-black jury will use the jury deliberations not as a search for truth but as an opportunity to strike back at white folk.

To that end, he is making much of the contention that U.S. Attorney Jay Stephens and his staff have "gone overboard, overzealous" in their efforts to nail him for "something that, at worst, was harmful to me personally."

The idea -- hardly beyond belief -- is that the prosecutor spent more time and money in pursuit of Barry than he would have if 1) Barry had been an ordinary citizen or 2) had been white. The first is both believable and justifiable. The second is contentious. Blacks tend to believe that the government went after Barry with special vengeance; that to deny that race was any part of it is to contend -- incredibly -- that no white officials are guilty of comparable offenses. Whites tend to believe that Barry's problem was not his color or even the specifics of his behavior but his arrogance, his catch-me-if-you-can defiance.

Barry has pinned his hopes on exploiting the difference. But he overdoes it. Even those who are willing to accept that there was a prosecutorial vendetta against the mayor will balk at Barry's contention that the federal authorities had tried to "kill" him. How?

"They had me ingest cocaine, crack cocaine, which could have killed me. I could have been dead now, with 70, 80, 90 percent pure cocaine."

His contention virtually concedes that the authorities knew that all it would take to get him to ingest crack cocaine, which he knew to be potentially deadly, would be to put him, an attractive woman and the crack in the same hotel room. And it also calls into question his oft-repeated statement that "never in my lifetime have I ever used any illegal drugs."

But that blanket denial, made after it was learned that he had made several visits to the hotel room of Charles Lewis (who was later convicted of drug offenses and who has said he smoked crack with the mayor), came before the videotaping at the Vista the night of his arrest.

His posture is no longer that of the innocent who had never used, seen or had any knowledge of drugs (except for alcohol, the self-admitted abuse of which prompted him to seek hospital treatment). He is no longer arguing that the evidence garnered by the government is open to guiltless explanation. No more is he boasting that they can't prove a thing. His latest position -- in my view, more the product of desperation than of optimism -- is that it is irrelevant whether the prosecution proves its case or not.

Barry knows that black Washington (and much of white Washington) doesn't want him sent to prison. But it doesn't follow that most of us want him found not guilty even if the government can show that he is; that's why a lot of us were hoping that he would plead guilty to one of the lesser charges, escape with probation and set about repairing his life.

He found us willing to believe that the prosecution was overzealous in pursuing him, less for what he did than for who -- and what -- he is. But now he's asking us to believe something quite different: that he should escape conviction because of who -- and what -- he is. He is asking us, or at any rate, one member of the jury, to reach the astounding conclusion that truth doesn't matter. Only race does.

Maybe the prosecution's case is as weak as Barry and his lawyers once insisted it was. And if it is, he ought to be acquitted. Our moral certainty that he did at least some of what he is accused of doing is not the same as legal certainty. If there is honest doubt, let him go.

But if there isn't ...

It will be a sad day if the mayor of the nation's capital is convicted as either a dope fiend or a liar -- or as a man whose political power tempted him to above-the-law arrogance; and it will be specially sad (for some of us, at least) that it should happen to a black mayor.

But what is sadder is his manifest assumption that he will be exonerated not by facts but by his race; sadder still if it he turns out to be correct.