Running a black candidate for president is either a savvy way of forcing concessions from the major Democratic candidates -- a device for getting black issues on the national agenda -- or it is an unconscionable waste of time, money and black votes. A interesting case can be made either way.

The Rev. Jesse Jackson, president of Operation PUSH, makes the case for the affirmative: black people, the most loyal of Democrats, have the least to show for their fidelity. The very predictability of their support of the Democratic nominee leads the Democrats to take them for granted and leads the Republicans to ignore them as largely inaccessible.

Jackson's notion, which may have wider support than a Jackson candidacy, is that running a black in the Democratic primaries will force discussion of the issues that are of central importance to blacks, so that even a losing candidacy would change the nature of the political debate.

In addition, he contends, blacks would have great brokering power at the Democratic convention if they arrived with a tightly controlled block of votes. A black candidate who fared reasonably well in a series of primaries would, under the theory, be the repository of those votes.

The NAACP argues the negative.Since a black candidate could not hope to win either the primary or the general election -- or even to arrive at the convention with a significant number of votes -- the candidacy would be a waste, or worse.

In a strongly worded resolution, the NAACP board of directors last week urged blacks "to take no steps, however symbolically attractive, which may have the effect of diluting the black vote." It called instead for a sharp focus on "the No. 1 priority: the defeat of the Ronald Reagan system of government, by casting every possible vote for the candidate who is most likely to achieve that goal."

Jackson would deny that the NAACP's goal is inconsistent with a black presidential candidacy. Under his formulation (at least until recently, when he hinted that he might run as an independent in the general election if he doesn't do well in the primaries) a black candidate would have his influence within the Democratic Party, helping to make certain that the issues important to blacks are given full consideration. After that, blacks would either vote for the Democratic candidate or stay home. In other words, the only way the process could help Reagan is if the Democrats nominated a candidate who failed to embrace the black concerns.

But are there "black" issues as opposed to Democratic ones? Are there black priorities besides employment, education and other "social issues" that a white Democratic nominee would not freely embrace, even without the impetus of a black candidacy?

NAACP chief Ben Hooks believes that the ouster of the "Reagan system of government" -- by which he means to include the "clones who would continue his system even if Reagan doesn't run for reelection" -- is the overriding black issue.

Perhaps the greatest value of a black candidacy would be the creation of a black political consensus, with its own priorities. The fact that the NAACP refuses to go along with the scheme suggests how tough that will be to accomplish.