In 1988, Sandi and Larry Zobrest sued a suburban Tucson, Arizona, school district that had denied their hearing-impaired son a taxpayer-funded interpreter in his Roman Catholic high school. The Catalina Foothills School District argued that providing a public resource for a private, religious school created an unlawful crossover between church and state. The Zobrests, however, claimed that the district had infringed on both their First Amendment right...