In this article, the author talks about Neal Frey, who for more than two decades has labored on behalf of Educational Research Analysts, a conservative Christian textbook-reviewing organization in Longview, Texas that was founded by the famously outspoken husband-and-wife team of Mel and Norma Gabler. When Mr. Gabler died at the age of 89, and Mrs. Gabler grew ill, it fell to their friend and protege, the 61-year-old Frey, to keep the reviews coming. Under the direction of Frey, who is assisted by his wife, Judy, the textbook shop has steadily evolved from the Gablers' era. While Mel and Norma issued textbook reviews as near-celebrities, storming public hearings and sitting for interviews with Phil Donahue and "60 Minutes," Frey, a former college professor, works in near-anonymity, making his points through the faxes and newsletters he sends to subscribers and textbook decisionmakers. Frey, like the Gablers, manages to kindle all sorts of debate. To his detractors, his stated pursuit of factual errors obscures his larger goal: to strip textbooks of any content that does not suit his deeply conservative worldview. And because he works in Texas--a vital market for educational publishers--his modest operation can have an enormous sway over the written materials used in classrooms across the country, his critics point out.