Harry G. Hutchison at George Mason was kind enough to send me his article just out in the Catholic University Law Review, Shaming Kindergartners? Channelling Dred Scott? Freedom of Expression Rights in Public Schools. At the core of his writing is an important question: "Why has the public square become so secular and so suspicious of religious expression?" In particular, Prof. Hutchison looks at public schools in pursuing this question.
The full cite for the artice is Harry G. Hutchison, Shaming Kindergartners? Channelling Dred Scott? Freedom of Expression Rights in Public Schools, 56 Catholic U. L. Rev. 361 (2007). A downloadable version is also available at SSRN at this link.