LONG AFTER she has left her desk as D.C. schools superintendent, Floretta McKenzie will be -- and deserves to be -- remembered with enormous respect and gratitude by those now closest to the trials and tribulations of public education in the capital city. But right now, her remarkable record of accomplishment poses a challenge: finding a worthy successor. This won't be easy, but it had better be quick. School Board President R. David Hall -- himself a significant factor in what has been a period of exceptionally good relations among the board, the superintendent, city hall, Congress and the White House -- wants a replacement on the job before Mrs. McKenzie leaves.

What kind of person should the city be looking for? As Mr. Hall has noted, finding someone who can run a school system is not too difficult, but finding someone who also "can understand and deal with the political structure is something else entirely." Those skills certainly defined the difference between successful superintendents -- Mrs. McKenzie, predecessor Vincent Reed and the popular Benjamin Henley -- and those who came from out of town with reputations as expert "educators," whatever that turned out to mean.

No one involved with the schools -- least of all Mrs. McKenzie -- would claim that either the system or what happens in the city's classrooms is at cruising speed. Test scores still lag behind national averages, and schools still have to deal with the pressures that plague urban schools all around the country. Physical plants in too many places are dilapidated. Supplies, including textbooks, can be slow in coming and old when they do get there.

Given all this, Mrs. McKenzie's accomplishments -- most notably the upbeat spirit and drive for improvement that have materialized -- have raised expectations as well as performances. More people and businesses and nonprofit organizations are eager to help the city's public schools, and still others are in the wings looking for cues. Mrs. McKenzie's act may be tough to follow, but the new opportunities it has made possible should help to bring forth a skilled, savvy and optimistic successor.