WHAT IS going on here? The mayor of the nation's capital, which also happens to be an American drug capital, is facing multiple drug-related charges. Yet he can walk into the D.C. Convention Center and nearly upstage Nelson Mandela. What is the Marion Barry mystique?

For weeks, prosecutors have paraded a procession of witnesses into federal court to testify that Barry, a self-professed "night owl," had sexual relations with some of them and used drugs in private homes, hotels, boats -- even the District Building. Yet when Barry appears at black churches and rallies in D.C., he receives a hero's welcome, and many black leaders nationwide rally to his cause.

For many whites, these are mysteries, plain and simple. But many blacks find nothing unnatural in their reactions, even while recognizing that the emotional waters are awfully muddy.

Many blacks recognize that although the fervor surrounding Barry's trial has much to do with the mayor's own behavior, the supportive response of African Americans transcends issues of his guilt or innocence. They see that in fact, Barry has become a cultural icon of blackness in D.C., and the response she inspires relates to broader sentiments simmering in black communities locally and nationally. His trial, in that way, has become a lightning rod, encouraging an increasingly vocal criticism of white America. Many African Americans believe that a kind of cultural apartheid rules the nation -- and their response is to assert their own black identity.now see the dawning of another cycle of black awareness: It extends from asymmetric hairdos and T-shirts that proclaim proudly and fraternally that "It's a black thing -- you wouldn't understand" to the blatantly black thunder of rap music exhorting young African Americans to "Fight the Power." It ranges from Spike Lee's cinematic examination of black psyches to Arsenio Hall, the first late-night leather coat and earring wearing TV host.

In short, black is back, at least among blacks.

The cultural resurgence also has political ramifications, especially for young blacks, who have been accused of political vacuity. In fact, notes Howard University political science professor Ron Walters, we are in the midst of an "emergence of black political consciousness," quite apart from traditional politics. And he adds, "When reality shapes that consciousness, and reminds {young blacks} of what they are about," political action will follow.

"We tend to become most conscious under conditions of advanced oppression, and certainly the Reagan years represent the most severe increase in oppression since the civil rights movement," said Na'im Akbar, a former head of the National Association of Black Psychologists. "I think people began to find that we were in trouble again."

Such disillusionment is prompting many blacks to challenge white establishment views about leadership and justice, and also to reassess the role of mainstream black leaders. This is the paradox: As more blacks get elected to districts with majority white populations, and as blacks assume more political and congressional leadership positions, their obligations to blacks seem to become diluted.

Amid the ascension of a new group of mainstream black politicians -- Gov. L. Douglas Wilder in Virginia, mayors Kurt Schmoke and David Dinkins in Baltimore and New York, among others -- many blacks who have not seen much improvement in their condition still long for black officials devoted to minority concerns. Consequently, such figures as Nation of Islam leader Louis Farrakhan, considered by many to be a fringe radical, are attracting curious black audiences that span the economic spectrum.

"We have to realize that there are two agendas," said Lewis Myers Jr., a Chicago lawyer who represents the Nation of Islam. "There is the movement agenda and there is the electoral politics agenda. Unfortunately, some of the movement leaders who are now politicians have confused agendas."

Few understand Myers's point as well as Marion Barry. Barry, a master tactician who first assumed office in 1978, built his political career on multi-faceted racial and neighborhood coalitions. With each passing term, however, his political base narrowed. In the twilight of his political life, Barry is now reduced to a hard core of black support, which he is trying to bolster by seeking sanctuary in the powerful black church and encouraging the notion that there is a white plot to destroy black leaders like himself.

"He is not only a black politician, but he has espoused black politics," Howard University's Walters said of Barry. "This angered some people in the white community. He has used race because in the political environment he operated, it made sense."

Barry has done this by tapping into black pride and disillusionment with politics in a majority black town where racial mistrust abounds. Many blacks suspect whites will do anything to regain control of politics and other aspects of life in Washington.

Above all, Barry has become a symbol of uncompromised blackness. Brash and flamboyant, Barry is perceived by many blacks as a real "brother," one who walks black, talks black, dresses black and flaunts his blackness in the face of an inhospitable white establishment. This is the man who sports a confident smile and a canary-yellow flower to court each day, in mockery of witnesses who "are singing like Ray Charles," as one street corner commentator put it.

Barry's defiance and personal style evoke comparisons with the cocky, charismatic Adam Clayton Powell Jr., who once proudly described himself as "the first bad nigger in Congress." Like Barry, Powell was an egotistical lover of women and good times. And if Barry's municipal record pales in comparison to that of Powell, who as chairman of the powerful House Education and Labor Committee did much to advance the civil rights movement, both were champions of black populist causes.

After being charged with tax evasion, Powell, like Barry, claimed he was a target of federal persecution. And while not all blacks were convinced of Powell's innocence, one contemporary said they stood by him because "he gave white folks hell." Similarly, many African Americans have protective feelings for Barry and seek to shield the symbol more than the person.

"They seem to be saying we're not going to crucify him," said Walters. "We understand he's done wrong, but he's a symbolic figure in many respects of black political evolution in this country. He went from being head of SNCC all the way . . . to mayor. He's not someone who went out and got a law degree and after a couple of years became mayor."

Even Democratic State Committee chairman Joslyn N. Williams, who failed in May to win approval of a resolution urging Barry not to seek a fourth term, said blacks want to present a unified front, anxious that the mayor not be humiliated even while agreeing that his political career is over. "It's incumbent on us to rally around our black leaders," he said, adding that blacks feel that "If anybody is going to issue any retribution, it ought not be outsiders, and that's white people."

As it happened, those black leaders who rallied most prominently around Barry are no strangers to controversy. Locally, Bishop George Augustus Stallings Jr., who broke from the Catholic church to form an Afro-centric congregation, has provided moral support to Barry. The mayor has also been bolstered by Farrakhan and Jesse L. Jackson, both of whom recently established political beachheads in the District. Even the media-savvy Rev. Al Sharpton put in an appearance at the courthouse in a show of unity.

In one sense, the combination of all this is extraordinary political and cultural theater: the Barry trial unfolding, political and racial players swirling about, powerful subplots being written against a backdrop of resurgent black awareness. But it has also left many D.C. blacks reeling. They are sorting through conflicting emotions; anger at the mayor for his actions, shame over the example being set for children, sorrow over the lost promise of '60s-era politics and revulsion over the way the federal government built its case.

"I don't think there is really a unanimous black Washington view on this," said Linda Williams, a Harvard University research fellow. A dominant theme, she said, is expressed by "a good number of people who characterize their position as not being support for Barry, but hostility toward the way white government officials have behaved."

The anxiety blacks and whites feel over the Barry case is compounded by suspicions on both sides. Some blacks are convinced that whites are watching with vindictive glee or view the matter in callously simplistic terms. On the other hand, many whites believe blacks use a double standard, and that Barry would have been run out town long ago had he been white.

Paul Buchbinder, a Ward 1 resident who is white, said his friends and colleagues feel the Barry case is cut and dried. They are annoyed, he said, by the unflagging support some blacks show for the mayor. "My white friends are either amused by it or angered by it," he said. "I have no respect for Barry, for Farrakhan, Stallings and Rev. Al coming to be a part of the Barry circus. The man should have resigned out of shame." A stronger view still was expressed in this week's Time magazine by neoconservative columnist Charles Krauthammer, who referred to Farrakhan, Stallings and others as "racist and nihilist . . .{a} motley crew of scoundrels, losers and liars."

Jesse Jackson recently observed that whites are concerned only with the facts of the case, while blacks "are concerned about context." And blacks across the country -- in barber shops and shopping malls, during family dinners and coffee breaks -- have expressed this contextual view: that the feds invested too much time and money in nabbing Barry for a misdemeanor, when those resources could have been better used going after major narcotics suppliers.

The context is also historical: Many blacks are troubled by the sense that white America has never grasped the depth of injustices committed against African Americans by a white society, from the evils of slavery to the present -- and that white America's response to the past has been perfunctory indifference.

Blacks and whites of course do share some common concerns -- for instance the view that nobody has any business doing drugs, especially mayors. But even so, some blacks tend to automatically reject assertions by whites that their values are the same. All too often they have seen whites label black heroes as outlaws. Such sensitivities are not unique; all ethnic and religious groups tend to see themselves, and their leaders, through special filters. Mark Plotkin, a WAMU political analyst who is Jewish, noted an analogous phenomenon among Jewish Americans who "look at Israel and don't criticize what Israel does."

You can see the racial fault lines most clearly when the debate turns to Louis Farrakhan -- a useful prophet to many blacks, a racist demagogue to many whites. Many blacks say they experience a cartharsis when he uses rhetoric and biblical allegory to, in effect, paint the world black. He instills pride with descriptions of a prehistoric world that began with dark people, empires that were ruled by dark people, times in which blacks were not enslaved or discriminated against. He reaches into history, rewriting the books to include roles that people of color have played through the ages. And he teaches black self-reliance and economic empowerment.

"To me, he is the one black person . . . who can best be looked upon as a positive force or representative for our people," said LaTanya D. Washington, a 28-year-old executive secretary who attended a recent Farrakhan rally. "He understands the plight from which we've come and the direction in which we should be going. To sum it all up, he's a cross between Dr. King and Malcolm X."

Yet Plotkin, one of only a handful of whites who attended a recent Farrakhan rally, said the sight of 10,000 blacks cheering wildly in support of the Muslim leader made him "feel tense. I didn't feel physically threatened, but remarks were made in starkly {racial} terms."

And a New Republic reporter, Andrew Sullivan, came away from the same rally with the certainty that he'd heard a message of hatred and paranoia. "That Farrakhan should quote the Gospels or the Koran makes him not less but more horrific," Sullivan wrote. "That he should cynically channel people's desire for self-help into hate is a tragedy second only to the desperation of those he appeals to."

A similar perceptual gulf, though perhaps not so wide, separates opinions about Marion Barry -- and will certainly persist. Whether Barry is found innocent or guilty, many will interpret the outcome in a racial light. And some blacks no doubt will continue to view the mayor as a symbolic force. They will understand that the full effect of the Barry case, like so much in American society, cannot quite be grasped by whites. They will know this: It's a black thing.