There is a side to the African American community that we tend to overlook. The dramatic plight and mass of the black under-class preoccupies us, properly enough. But upwards of four out of 10 African Americans qualify as middle class.

To begin with, that means they have professional, white-collar or skilled blue-collar occupations. But it also identifies some of their values and aspirations.

It is of particular importance for Jews to understand this phenomenon. Louis Farrakhan's march on Washington, for example, largely consisted of middle-class men. That is both ominous and encouraging.

After all, Jews have learned the hard way about the principle of the "poisoned good," sometimes known as the "rat-poison" rule for measuring leaders. It is well known that rat poison can consist of about 90 percent good corn and 10 percent strychnine. But no one says that because rat poison contains mostly good things, we should therefore ignore the small amount of bad. To do so would be fatal at the dinner table, and it is fatal in politics.

Not all rascals or wrong-minded politicians qualify under the rat-poison rule, but when they do, their leadership has to be 100 percent rejected despite their 90 percent good statements or deeds. For that reason, although agreeing with much they had to say, mainstream Republican leaders totally rejected David Duke and mainstream Jewish leaders totally rejected Meir Kahane.

Both men crossed a line of malevolence: They attempted to reduce the humanity of other groups and whip up hatred against those groups as a whole. Overt racism is one line in the human sand that we cannot allow a political leader to cross. There are special evil and destructive consequences. Louis Farrakhan has clearly crossed that line.

On the other hand, to a large extent, the African American men who gathered in Washington, D.C., were middle class or middle-class oriented. They want to succeed. They want to be independent of government aid. They want to fight drug-infested neighborhoods and the dissolution of the family.

In fact, most of those displaying that middle-class consciousness want to be integrated, that old civil rights word. They know that is the only way they can make it. But they want to help each other toward that goal by dealing with each other, buying from each other, helping each other's businesses. That is one way they can help their whole community rise, including those less fortunate than themselves. And that is the way all large immigrant groups have operated in America, including Jews.

That is the good in Farrakhan's message, without the poison.

However, his message is laced with poison, and for that reason, he must be 100 percent rejected and shunned, lest his strychnine becomes mixed with everyone's corn. But we cannot stop at that rejection.

The solid aspirations of the African American middle class, which has grown so substantially since the civil rights revolution, and was expressed by so many in Washington, must be encouraged. When the Latino and Asian American middle class make it, they tend to fit into mainstream America. But the black middle class is still more segregated and self-segregated because of the uniquely tragic and perverse history between them and America. And they are still weighed down by the continuing misery in the ghettoes that they escaped.

Few middle class blacks have yet swallowed Farrakhan's poison, but they could someday if the reasons for their alienation are not lightened. More of them could swallow that poison if we smear them all prematurely with the tar of Farrakhanism or, conversely, if we become afraid to insist on the reasons for rejecting Farrakhan 100 percent.

That is why many Jewish agencies have supported most of the aspirations of the marchers while simultaneously rejecting the march's founder. The stability of the African American middle class is so important to the American future that we must walk that difficult tightrope.