The death this week of the great East L.A. math teacher Jaime Escalante revived the question that first came to mind when "Stand and Deliver" hit movie screens in 1988: Why can't we just replicate the Escalante magic thousands of times over? Imagine what educational heights might be attained.

Unfortunately, it's not so easy. Escalante was a mold-breaker, a force of nature in the classroom. Years before the term "achievement gap" was coined, he took under his wing the low-income minority students who weren't considered star material by conventional thinking and pushed them to the top levels of achievement. His keen mind, passion and initiative are not simple qualities to clone.

But Escalante's death reminds us of the importance of finding, training and retaining excellent teachers. Study after study shows that the quality of teachers and principals is the key factor in how well students learn. It's also the aspect of education that is most consistently undervalued by the school reform movement, which has emphasized standardized tests and curriculum.

The components that make up a great teacher are not a mystery, and there is much that policy leaders could do to bring us closer to the ideal Escalante personified.

Effective teachers tend to have been first-rate college students, often attending selective universities,