Ken Mundy -- "R. Kenneth" on the shingle of his K Street office -- is a successful black lawyer in Washington. He is a principal in his own firm. His annual income is not far below the prestigious six-figure threshold that is considered an indisputable sign of having "made it" in the nation's capital.

When folks talk about top-flight black courtroom lawyers in this town, they talk about Mundy. They say he is a good black lawyer, not to imply that he is good for a black, but rather that he is a good lawyer by any standard, and he's also black.

Melvin Downing went to Mundy when Dowing was accused of chopping three men to death with a machete in a Northeast Washington fish market. A survivor identified Downing as the killer. But Mundy walked Downing out of the courtroom on a not-guilty verdict.

Last year, Mundy walked teenager Terence Johnson out of a Prince George's County courtroom with a 25-year sentence for manslaughter instead of the anticipated double life imprisonment terms for murder-one. Johnson was charged with slaying two county police officers. "You should be thankful," the judge told Johnson, "thankful that someone had the foresight to hire Ken Mundy as your attorney."

Mundy is, by many accounts, the Edward Bennett Williams of Washington's black community. But unlike Williams, a legendary white lawyer whose firm has a comfortable collection of retainers from corporations to keep it going, four of every 10 dollars Mundy earns come from personal injury cases -- a rarely prestigious branch of law practice, only a few steps removed from chasing ambulances.

This is part of the legacy of black lawyers in Washington that Mundy shares with dozens of colleagues who are not as well-known.

And that legacy is a major reason why J. Clay Smith Jr., president of the predominantly black Washington Bar Association, says he has some serious concerns about the impact on black lawyers of no-fault automobile insurance proposals now under consideration by the D.C. City Council.

"Depending upon the level of the no-fault concept (adopted)," Smith said the other day, "it may well make private practice (for black lawyers) in the District of Columbia extinct."

The great no-fault debate of 1980 begins today. A committee of the City Council has hearings scheduled on four proposals to replace the city's present insurance system, under which about half of the drivers are estimated to carry no insurance at all.

Some of the proposals under discussion would set up a no-fault system in the District. Under a no-fault system, many of the claims now settled in court would be paid automatically. The lawyers who now argue those cases would have to find something else to do.

Every one of the proposed boons of no-fault insurance, from lower premiums and larger rewards to smaller caseloads and less abuse, are open to dispute, based in large part on the experiences of other states where such systems are already in use. About the only thing most sides agree on is that some kind of compulsory auto insurance is needed in the District of Columbia. s

Implementation of a no-fault system would further deplete the ranks of black lawyers now in private practice, Smith fears. Many are more dependent on personal injury cases than their white counterparts, and have fewer options if a significant number of personal injury cases disappear, he said.

Smith contends that blacks in private practice have provided a pool of legal resources for commumity consumers like churches, neighborhood groups and civil rights organizations, who often get legal services free or at reduced rates.

"Legislation that argues to be preconsumer has to be looked at for the potential impact it has on the consumer," Smith said. "You might gain on one end and lose on the other."

No-fault proponents, like consumer advocate Ted Johnson, have a penetrating counter-argument. "I don't think the system of insurance, which everybody contributes to, should be a welfare system for the legal profession," Johnson said. "If a lawyer's competent to do only certain cases, then I question if he should be in the legal profession."

No-fault will be a tough issue for the City Council. On the surface, it is likely to be played out before a backdrop of statistics on uninsured drivers, horror stories of catastrophic crashes that left lives and life savings tangled in the wreckage of unpaid bills.

The a secondary theme will undoubtedly be the fate of black lawyers, an interest group that few politicians want to ignore because of their stature in the community, and because they vote regularly and contribute to political campaigns.

Many of the black lawyers who stand to lose if no-fault is adopted are among the untold stories of Washington, especially in recent years, even though in many instances they are the type of lawyers with whom Mr. and Mrs. Everyday Black Washington are likely to come in contact.

These are the neighborhood lawyers, who get many of their clients through the grapevine rather than the expense account lunch.

"They're only on the edge. The run-of-the-mill cases are the cases they live by," said 70-year-old Lincoln Johnson. "They have that as a staple because they do not have the contacts to have the cream of the law business."

Clay Smith and those he represents do not want the battle of no-fault to be viewed as consumer against non-consumer; the profession class against the grass roots, or even black against white. After all, many of the lawyers who will lose business are white.

Rather, for them it will be a question of what the system giveth and what it taketh away; who wins and who loses when the elected government takes a stand, and whether those who, in Smith's view, have denied black lawyers' progress for so long can now deny them livelihood in the name of the consumer.

Smith seems to be asking an awful lot for the issue to be viewed primarily in those terms, but nowadays its fair to say that most of the easy victories have already been won.