The sudden resignation Wednesday of Lauro Cavazos as U.S. Secretary of Education can best be described as the culmination of a bitter-sweet experience.

Sweet because of the great promise with which this outstanding educator began this demanding assignment, becoming the first Hispanic American ever appointed to the Cabinet.Bitter because, after a little more than two years on the job for Cavazos, that promise remains largely unfulfilled.

Yes, Cavazos brought highly impressive credentials to the post, having served as president of 23,000-student Texas Tech University following a distinguished career as a medical scientist and educator plus department chairman and dean of the Tufts School of Medicine.

Yes, during his brief tenure in Washington, the soft-spoken, gentle Cavazos helped heal some of the wounds inflicted on the education profession by his abrasive predecessor, William Bennett.

Yes, Cavazos embraced all of the proper principles. Among other proposed reforms, he called for "deregulation" of education, allowing parents a choice in selecting schools, thus improving schools through competition. In addition, he called for more parental involvement in a child's entire school career, more focus on early childhood education instead of just leaving youngsters in day-care arrangements, more curriculum reform and more accountability for teachers and school administrators.

But Cavazos also kept a low public profile and backed away from some of the bureaucratic in-fighting that is always unpalatable but sometimes necessary to be effective in Washington.

As a result, Cavazos came under fire from two key sources. Educators, maintaining that student achievement is still declining, faulted Cavazos for not championing their cause strongly enough to suit them. Moreover, powerful figures close to President Bush blamed Cavazos for not helping the chief executive make good on his pledge to become the "education president."

For such shortcomings, real or fancied, President Bush himself bears much of the responsibility. Faced with a souring economy and a persistent deficit, the President has been forced to undertake some belt-tightening throughout the federal establishment, including education. Likewise, preoccupied with a variety of foreign challenges from the apparent collapse of communism to the Persian Gulf crisis, Bush has suggested a number of promising education reforms but failed to keep pushing for them.

One lesson of this experience is that the next secretary of education needs to be someone who won't shrink from using this Cabinet post as a pulpit from which to preach the school reforms espoused by Cavazos - and then to keep at it even at the risk of nagging.

Another lesson is that the secretary of education, like any other presidential appointee, can be no more effective than the chief executive lets him be through persistent backing or the lack of it.

What's ultimately at stake is not just the effectiveness of whoever succeeds Cavazos but the future of the younger generation and of the nation itself. When education falls short, America becomes less competitive and its quality of life suffers. School dropouts alone cost society an estimated $228 billion a year. The education deficit, then, ought to be considered just about as important as the federal deficit or almost any foreign crisis to become before the president.