THE OTHER DAY, my son, aged 9 and armed with nothing more than several preliminary lessons in karate, lost his bus token and walked home from school. He walked slowly, stopping off at a nearby hotel to take in the lobby and ride the elevators, and by the time he arrived home, happy and having a very good time, the other members of his family were at their wits' end. The world, as we know, is full of creeps who prey on kids.

At the moment, one or more of them is loose in Atlanta where he, she or they have killed at least 20 children, maybe 21, most of them poor, all of them black. The nation is gripped with this tragedy. We see pictures of the dead children and fear for our own. We see the bereaved parents and know that what makes them different from most Americans is not their race, but their awful luck.

But now the Mayor Barry and some other black leaders are telling us that race is the salient factor. It is race, they say, that led the Atlanta cops to allegedly ignore the disappearance of the children and it is race that has allegedly caused the nation not to care about the kids and it is race, race, race that accounts for that fact that the killer, or killers, has not yet been caught.

"A certain mood exists in this country, encouraged by the leadership, that it is all right to do anything to black people," said Marion Barry. "Now I maintain that if those were 21 white people we would have no problem" getting the federal government involved. That sentiment has been echoed by other black leaders who have been attempting to turn the death of these kids into something it should not be -- a racial issue.

Every minority group has a tendency to become possessive about a tragedy that strikes one or more of its members. Thus some incidents become a "women's tragedy" and others become "black tragedies" and still others are labeled as Hispanic or Jewish or Italian or whatever. There is nothing wrong with it being, in some way, a black tragedy. Those are, after all, the facts. The kids were black. But that does not mean that whites don't care or they are in some way responsible or that this is the sort of thing that could only happen to black people. It is a fact, after all, that 33 white children disappeared in the Chicago area and we never heard a thing about it until the mass murderer, John Wayne Gacy, was caught and the gruesome cache under his floorboards revealed. And it is also true that 26 white children disappeared in Texas and that this, too, was not noticed until their killer, Elmer Wayne Henley, was finally caught.

It is not true, either, that the federal government has been unresponsive to the Atlanta black community. In February, President Reagan announced the formation of a task force under the direction of Vice President Bush to aid Atlanta in its investigation and just last week said he would send nearly $1 million to the city to help find the killer and to set up a 24-hour hotline for parents and children. Twenty-six FBI agents have been assigned to help the Atlanta police.

This Atlanta tragedy has been going on a long time. Recently, it has coincided with what seems to be a revival of racism, especially racism of the Ku Klux Klan variety, and it has also coincided with an attempt by the Reagan administration to reduce or eliminate programs that affect large numbers of black people. It is understandable for blacks to feel besieged. In a sense they are.

But is the obligation of the political leadership to distinguish between fact and fear, truth and sentiment, to acknowledge what the government has done and not use the dead children as ammo in the political struggle with Ronald Reagan. It's not the cutback in the food stamp program that's killed those kids and it's not Reagan's position on affirmative action that killed them, its a killer or killers -- maybe white, maybe black, but either way, not a government program.

And it is also the obligation of the political leadership to not use this tragedy in some sort of political way, to create an us-against-them atmosphere to appeal to a certain electorate or turn out the vote and get the juices stirring. It is kids we are talking about -- not black kids or white kids, but just plain kids. It is tragedy enough that they are dead. It would be even a worse tragedy if their deaths were used to divide us racially.