Today the Iowa Supreme Court unanimously overturned the state's ban on gay marriage, concluding that it violates the state constitution's guarantee of equal protection. That provision, the court said, "is essentially a direction that all persons similarly situated should be treated alike." After concluding that same-sex and opposite-sex couples are "similarly situated" with respect to the purposes of Iowa's civil marriage law, the court applied a level of scrutiny between the "rational basis" test used for most laws challenged on equal protection grounds and the "strict scrutiny" used for laws affecting "fundamental rights" or involving "classifications based on race, alienage, or national origin." Examining the official rationales for the gay marriage ban one by one and finding each of them unpersuasive, the court concluded that the law could not survive "intermediate scrutiny."
I like the policy outcome here, and I sympathize with the argument that the principle of equal protection should compel the government to treat gay and straight couples in an evenhanded manner. But this decision, like the California Supreme Court's similar ruling last year, seems to be another example of result-oriented jurisprudence that ultimately undermines a constitution's ability to constrain government action and protect individual liberty. If you read the court's analysis as it goes through the arguments for a gay marriage ban and (correctly, in my view) finds each of them wanting, it's hard to see how this process differs from what legislators do.
It's clear that the Iowa constitution's equal protection clause, at the time it was adopted, was not understood to prohibit a law limiting marriage to a man and a woman (assuming the issue would even have been intelligible). So the basis for saying that such a law is inconsistent with that clause today has to be an evolving understanding of what equal protection entails, especially regarding what it means to be similarly situated. But barring a constitutional amendment, judges can implement this new understanding only by reinterpreting the clause to mean something it did not mean at the time it was written. That sort of license can lead to all sorts of mischief, as the evolving understanding of the U.S. Constitution's Commerce Clause (to pick one especially pernicious example) illustrates.
Update: The California Supreme Court decision legalizing gay marriage was overturned by last fall's Proposition 8, a petition-initiated ballot measure that amended the state constitution to define marriage as a union between one man and one woman. A constitutional amendment is less likely in Iowa, where the process is more cumbersome (as it should be):
To amend the constitution, the Legislature would have to approve a resolution calling for the change during the current General Assembly. The Legislature that takes office in 2010 also would have to take action.
If approved in two consecutive General Assemblies, voters would decide the issue in a statewide election. If not taken up this session, the soonest the issue could go on the ballot would be 2012.
Although Republican legislators will try to pass a resolution, the Democratic leadership of the General Assembly has no interest in overturning the Supreme Court's ruling.
[Thanks to Mark Lambert for the tip.]