Any discipline has a canon, a set of themes that organize the way in which people think about the discipline. Or, perhaps, any discipline has a number of competing canons. Is there a canon of constitutional law?(1) A group of casebook authors met in December 1999 to discuss the choices they had made-what they had decided to include, what to exclude, what they regretted excluding (or including), what principles they used in developing their casebooks.(2) Most of the authors were affiliated with law schools, but some had developed coursebooks for use in undergraduate political science and constitutional history courses. Each participant was asked to write a short paper describing the canon of constitutional law, either as reflected in his or her choices, or in the range of materials available in the field.(3)
What do coursebook authors' reflections on their choices show about the canon(s) of constitutional law? In my view, three themes pervaded our discussions, and many of the papers that follow. A crude classification is that one theme involves the focus of the constitutional law canon, another involves the canon's substance, and the third involves the audience for constitutional law studies.(4)
Participants expressed substantial interest in teaching something about the Constitution in non-judicial settings. This interest takes several forms. In what seems initially to be the narrowest form, the interest lies in ensuring that students know what happens next. That is, what happens after the Supreme Court decides a constitutional question? Students ought to know, many participants thought, that Congress enacted a statute requiring the armed forces to allow service members to wear "item[s] of religious apparel" if doing so would not "interfere with the performance of the member's military duties," after the Court held that the Constitution did not require such an accommodation.(5) Perhaps more interesting are legislative reactions to decisions finding a statute unconstitutional. After United States v. Lopez,(6) for example, Congress re-enacted the Gun Free School Zones Act, this time including findings and a jurisdictional element making it an offense to possess (near a school) a gun that had moved in interstate commerce.(7) Instructors could use this statute to probe the meaning of Lopez: How important is Lopez as a case about fundamental principles of federalism if its strictures can be overcome by a statute containing findings and a jurisdictional element?
A broader discussion might be introduced if students knew that legislative vetoes persist after Immigration and Naturalization Service v. Chadha.(8) Here instructors might ask why legislative vetoes persist and thereby open a discussion of the way in which political forces might exert a hydraulic effect on legislation, by which I mean that political forces will seek their own level no matter what the Supreme Court says the Constitution allows. This discussion, in turn, might be linked to others, such as one way of presenting the legislative response to the Court's desegregation decisions. Here at least two paths seem open. Along one, the class could explore Gerald Rosenberg's argument about the conditions for successful judicial intervention, based on the Constitution, in controversial public policy questions.(9) Along another, it might use these discussions to examine Barry Friedman's account of constitutional adjudication as a process of dialogue between the Supreme Court and Congress.(10)
The Constitution plays another role in non-judicial settings: Non-judicial actors sometimes discuss the Constitution in the ordinary course of their business. Sometimes, as in the case of impeachment, they do so because no one else has authority to do so. Sometimes they do so because they believe they have a constitutional duty to consider the constitutionality of legislative proposals.(11) Many participants believed that students would profit …