I. Originalism and Changing Circumstances.

How could this be so? Whether a law violates original meaning of the Constitution depends not just on the words of the text, but on relevant factual circumstances. For example, the Fourth Amendment bans “unreasonable” searches and seizures. Whether a search is reasonable depends at least in part on the state of technology, the likelihood that the search will catch a criminal, and other factual circumstances. As technology changes and our knowledge increases, a search that could be considered reasonable at Time A might not be reasonable at Time B, even though the meaning of the Fourth Amendment has not changed at all.

The constitutionality of sex discrimination is a particularly telling example. Steven Calabresi and Julia Rickert have shown that the original meaning of the Fourteenth Amendment constrains discrimination against women if that discrimination lacked a compelling rationale beyond a desire to subordinate them as an inferior “caste.” But 19th century understandings of biology and social science led most people to believe that a wide range of laws discriminating against women were constitutional because they were rational responses to fundamental differences between the sexes. Today, much of the factual understanding of the 19th century has been discredited, with the result that many laws that perhaps could legitimately be upheld in the 1870s are now unconstitutional. I expounded on this point in greater detail here:


II. Implications for Same-Sex Marriage.

As I have previously argued, laws banning same-sex marriage discriminate on the basis of gender, much like 19th century laws banning women from various occupations. For many decades, the state of our knowledge was such that it seemed inconceivable that same-sex couples could raise children, form committed long-term relationships, play a stabilizing role in society, and otherwise carry out the various functions associated with opposite-sex marriages. Today, however, we know that these assumptions are false or at least greatly overstated. Just as we now know that women can be effective lawyers and that phrenology is bogus.

We may not be able to pinpoint the exact date when knowledge advanced to the point that courts were justified in striking down laws excluding women from various occupations. I would tentatively say it happened soon after various states first allowed women to enter many professions in the late 19th century, and experience quickly showed that no great disaster occurred as a result. Still, a good case can be made for a different date. But all a court needs to know is that the relevant date occurred sometime before the day when it has to make a decision in the case before it. And what is true of other forms of sex discrimination is also true of laws banning same-sex marriage.

Finally, I recognize that originalism is far from the only theory of constitutional interpretation. I myself do not believe that it should be the only factor courts take into account. In this post, I focus on originalism because I think it obvious that most “living Constitution” theories readily allow for situations where a law that is initially constitutional becomes unconstitutional over time.

UPDATE: The above analysis could potentially be reformulated as saying that laws banning same-sex marriage were unconstitutional as soon as the the Fourteenth Amendment was enacted in 1868, but people just didn’t have enough knowledge to figure it out until much later. But, for purposes of judicial review, the key issue is when real-world courts had enough evidence to justify striking down a law like Proposition 8. And that time could easily be later than the point at which a court with perfect information would have been justified in doing so.