A thought that occurred to me as I was reading Judge Posner’s opinion on same-sex marriage concerns the relationship between originalism and rational basis review. Here are my questions:
1. What is the originalist basis for saying that any irrational law is unconstitutional? Are there Founding-era cases or authorities that support that proposition? How about cases from the late 1860s?
2. If not, then rational basis review must be an exception to originalism. After all, a court undertaking that inquiry does not ask whether a law was rational given the perspective of 1787, 1791, 1868, etc. Instead, judges are asked to decide whether a law is rational now. How is that exception justified?