WITH JUST TWO more changes, the leadership of Washington's public school system could be the best since board elections began. Without these changes, the board could become again the political circus that nearly destroyed public education in this city. This is what District voters should consider when they go to the polls Tuesday.

These candidates deserve election:

At-large (vote for two): David Eaton, Phyllis Young.

Ward 2: R. David Hall.

Ward 3: Wanda Washburn.

Ward 8: Virginia H. Howard.

Today's school board is a generally constructive, low-profile, serious body that works well with Superintendent Floretta McKenzie. She has earned this support for involving civic and business leaders, parents, teachers and adminstrators as never before in contributing time, talent and supplies to the classrooms.

Sensible leadership of the board has made a big difference. Mr. Eaton, a former board president, and Mr. Hall, the current president, have set the tone and won the respect of colleagues. Mrs. Washburn is running unopposed, not because of apathy in her ward but because of her vigorous concern for children across the city.

By these reasonable standards, voters should reject incumbents Barbara Lett Simmons (at-large) and R. Calvin Lockridge (Ward 8). Their confrontational and often tasteless rhetoric has no place. Their past pledges of fairness to all wards and of support for Superintendent McKenzie ring hollow.

Phyllis Young is more than qualified for Mrs. Simmons' seat. She was an organizer and first president of Parents United for D.C. Public Schools, an organization that pressed successfully for adequate budgets and for better relations between the school system and city hall. A native Washingtonian who has lived in five of the city's wards, she has worked for handicapped children and foster care and to reduce teen pregnancies and drug abuse. Her election would do more than replace someone else; it would materially strengthen the board.

Virginia Howard has taught English at the University of the District of Columbia and its predecessors for 20 years. She is highly regarded by knowledgeable members of the school board and by the D.C. Council member from Ward 8, Wilhelmina Rolark. The danger is that the ward will split its vote among five challengers and wind up still ill-represented. If the voters of Ward 8 are tired of second- rate service and want respected representation, they should join behind Mrs. Howard.