Fairfax County's normally sensible School Board has gone off the rails in its campaign to shoehorn more Fairfax students into the University of Virginia. No doubt it's understandable. School boards take a lot of pounding from parents who want their children admitted to good colleges, and up to a point that's a good thing. That kind of parental interest is the political base for excellent schools. But things have arrived at a point in Fairfax at which the school board seems to be demanding admission of more of its graduates even at the cost of eroding the quality that attracted them to the university in the first place.

Fairfax County is already significantly overrepresented in each year's freshman class at the university. There are several ways in which it could accommodate still more youngsters from Fairfax, and all of those ways are undesirable. It could admit fewer students from other states. About a third of the university's entering students come from outside Virginia, and some of the school board appear to think that's too many. The trouble with that idea is that students contribute to each other's education, and when a college draws from too narrow an area it runs a risk of becoming narrow and parochial. There's a pretty wide consensus that a university cannot take its ratio of in-state students much above two-thirds without suffering for it.

Another thought current in Fairfax is to push out some of the applicants from other parts of the state when their test scores are not quite as high as those of the Fairfax applicants. But that raises a basic question of fairness and equal opportunity. A very high proportion of the state's best academic high schools are in Fairfax County. Most of the state's children go to schools that send far fewer graduates to college, and those few get far less intense preparation than the Fairfax schools routinely provide. To choose the university's students simply on the basis of test scores when there are such wide differences in the quality of the coaching for those tests would be an injustice.

After all, it's not as though Fairfax were full of high school graduates who couldn't get into any college. There will always be some students, unfortunately, who suffer the disappointment of not being accepted for the university at Charlottesville. But Virginia offers many other choices. If the Fairfax County School Board's campaign were to succeed, it could only damage the balance of the state's large system of colleges and universities. That all suggests an odd loss of perspective on the part of people who, themselves running a fine school system, ought to know better.