Local Evidence in Constitutional Interpretation

The Supreme Court frequently relies on state law when interpreting the U.S. Constitution. What is less understood is the degree and manner in which the Supreme Court and other federal courts look to local law. Although it has gone largely unnoticed, there is a robust practice of acknowledging and accounting for local law in the course of constitutional interpretation. Local evidence may inform the decision whether to recognize a constitutional right, it may inform the interpretation of the right, and it may inform the remedies for a constitutional violation.

For example, the Supreme Court has examined local enforcement patterns to decide whether a constitutional right is violated in death penalty jurisprudence. In substantive due process rulings, a lack of local enforcement has provided support for recognizing constitutional rights. Judges seek to minimize remedies for constitutional violations that might disrupt local law and practice. As is done with respect to states, judges consider whether local practices are outlying or common.

Judges also look to local law and practice to inform the development of constitutional norms. This Article analyzes and defends reliance on local law and practice in constitutional interpretation not to advocate localism or deference to local practice, but as evidence in constitutional interpretation. Using local evidence in constitutional law is particularly important at a time in which empirical research on local-level data is providing information that can better inform constitutional law.