When I was a kid, my grandmother was a never- ending cause of embarrassment to me. Old and illiterate, superstitious and religiously observant in an eclectic way, she embarrassed me before my friends with her exotic manners. She spoke only Yiddish. She was toothless. Once, she took some freshly caught fish and cleaned them in the driveway. She sat on a chair, fish scales all around her, as neighbors gawked. I was mortified.

I was mortified, too, by her passionate embrace of Julius and Ethel Rosenberg, the so-called atomic spies. To my grandmother, the case against them -- even after they had been convicted -- was patently obvious: They were Jewish. Everything in my grandmother's experience led her to that conclusion. Anti-Semitism defined her life, made simple what was terribly complicated. It was her Rosetta stone. It explained everything, especially everything bad.

My grandmother comes to mind now because of a friend-of-the-court brief filed by the National Black Leadership Roundtable on behalf of Mayor Barry in a suit ultimately rejected by the court. The roundtable, an umbrella group comprising 300 black organizations, represents most of the nation's black leadership. In essence, it said Barry was being pilloried in the press and investigated by the government because he is black. It lumped the investigation of Barry in with those of other black officials and called them all "racially motivated."

The perception among some or many blacks that black leaders like Barry are being persecuted or prosecuted on account of race is understandable. What anti-Semitism was for my grandmother, racism has been for blacks: not only a factor in their lives, but a real explanation of their plight. Everything from poverty to, until recently, the inability to vote was caused by racism. That racism persists is also indisputably true; it now manifests itself more subtly but, to some blacks, no less effectively.

Jews and blacks are not the only ones who sometimes wear their sensitivities on their sleeves. Mario Cuomo, an educated man and no immigrant, has a virtual hair trigger when it comes to the word "Mafia." He considers it an anti- Italian slur, and, certainly, the word is sometimes used that way. Cuomo comes by his sensitivities the hard way. A straight-A student and later a brilliant appeals court clerk, he nevertheless found that no major law firm would offer him a job. He saw this as an example of anti-Italian sentiment in the New York legal establishment -- and he was probably right. His experience made him sensitive, even raw, and sometimes he sees prejudice where it doesn't exist. At a now-famous press conference, for instance, he denied the obvious about organized crime: "You're telling me that {the} Mafia is an organization, and I'm telling you that's a lot of baloney."

Homosexuals, too, share a history of discrimination and persecution. As a result, it's now hard for some gays to differentiate between hostility toward them and concern about AIDS. Of course, the two are often combined, but there are some people -- like those who proposed closing bathhouses -- who were animated by concerns about public health and not by revulsion at the gay life style. Understandably, it was difficult for some gays to tell the difference.

Black political leaders -- indeed, much of the black community -- are no different from Jews, Italians, gays or any other minority group in this regard. But neither racism nor anti-Semitism explains everything. What both infuriated and embarrassed me about my grandmother was the conviction that she was being used -- that she was an ethnic patsy. Activists who could not defend the Rosenbergs with facts appealed to my grandmother and others on religious lines. They pronounced the Rosenbergs victims of anti-Semitism when, in fact, they were nothing of the sort. They were adjudicated traitors who happened to be Jewish.

For whatever reason, black leaders are doing somewhat the same thing. They ignore the fact that some of the prosecutors investigating Barry are themselves black. They portray leaks to the news media as exceptional and racially motivated, when they are in fact routine and have also plagued white politicians such as Spiro T. Agnew. They accuse whites of attempting to wrest political power from blacks, but such an outcome would be impossible in majority-black Washington. Moreover, the U.S. attorney's office has had its successes. More people from the Barry administration have been sent to the clink than from some New York Mafia families.

The obligation of leadership is to lead, not to pander to the prejudices or insecurities of its constituents. Virginia Lt. Gov. L. Douglas Wilder made this point when he told fellow black leaders recently, "A public official is a public official" -- neither black nor white. Corrupt politicians of any race are leeches on the community. They are true egalitarians, taking from black or white citizens without regard for race. If they are white, they often say -- as Agnew did -- that they are victims of a political vendetta. If they are black, they say that -- and that they are the victims of racism. They very well may be both, but the ultimate judges of this are the juries that hear cases after charges are brought. For blacks, it would be tragic if they were victims of racism twice over -- the first time by whites, the second by black politicians who cite racism to obscure the issue of possible corruption. ::