It was early in the morning and I was walking to work when out of a building came Jesse Jackson. The civil rights leader was in mufti, dressed in a business suit, and accompanied by only one aide instead of his usual claque. I considered saying hello, reminding him that we had met and then going on my way.

Then I spied the kid. He was black, about 16 years old, and walking fast. But when he saw Jackson he stopped dead in his tracks and his mouth fell open. Even when he started to walk again, he did so slowly and deliberately, looking over his shoulder at Jackson all the time.

Now it could be that the kid would have reacted the same way to Walter Mondale or John Glenn, but I doubt it. I doubt he would even have recognized them. But he did recognize Jackson and he followed him with his eyes, his mouth open all the time. Only when Jackson was driven away did the kid resume his brisk walk.

It was a small incident, but it made an impression. I know nothing of the kid and for all I know he is a political junkie and has a scrapbook filled with pictures of Democratic candidates. But if he is a typical Washington teen-ager, he knows almost nothing about politics, cares nothing about politics and believes--no, knows--that it has nothing to do with him. But he did know Jesse Jackson.

Now Jackson is considering whether to run for president ostensibly as a way to get more blacks registered and involved in the political process. It is a risky proposition. Many black leaders are against the idea for policy as well as personal reasons. Jackson may be popular among blacks in general, but some black leaders consider him nothing but a grandstander--a silver-tongued orator who's all talk and no action.

For other blacks, Jackson's potential candidacy looms as a no-win proposition. They know he can't win the nomination and fear he can only hurt the black cause. They think his candidacy could siphon off enough black votes to ensure the nomination of a conservative Democrat--no big deal when it comes to civil rights, where all the candidates are in agreement. But there is no such agreement on the economic issues that are paramount to blacks. For this reason, some blacks think a Jackson candidacy could be a debacle.

I have my own problems with Jackson. I am never sure what his program is. His rhetoric is a mixed bag. Some of it is admirable and inspiring, but some of it is simplistic and demagogic. (His reference to Japanese workers as slave laborers is hardly a sophisticated analysis of our trade problems.) Mostly, though, I have a hard time figuring out what happens after the last echo of a Jackson speech has died away.

But on the day the kid spied Jackson, the newspapers reported on the number of National Merit Scholarship semifinalists from Washington. There were 52--all but three of them students at private schools. Perhaps some of the private school semifinalists were black, and maybe the ones from the one public school as well. But that does not change the fact that the entire Washington public school system, 94 percent black, could only come up with three semifinalists.

What we have here in raw figures is the outline of a national tragedy. There are many causes for it and probably many solutions to it, but one of them has got to be simple involvement--getting black youths involved in what is often called the system. They have to be made to understand that despite all the rhetoric to the contrary, it is their system, too, and it will respond to them if only they know how to push the right buttons.

Voting is one such button. If Jackson can get that kid to respond, if he can interest him in voting, if he can get him to understand that his future is in his own hands, then his candidacy will have accomplished more than any of the others that fall short of the nomination and be worth any of the problems it creates.

For Jesse Jackson, the ultimate challenge is not the chance to broker the convention or flatter his own ego. It is, instead, a kid in sneakers. If he can interest him in voting, then Jackson is a winner no matter what. In fact, we all are.