Professor Kerr favors legalization of same-sex marriage. He considers a standard of constitutional review - the rational basis test - for laws that limit marriage to heterosexual couples. He offers his interpretation of how it might be applied to defense of marriage acts - without endorsing its application:
When the state takes on the task of defining who should receive a government benefit, and that definition requires a great deal of complicated linedrawing, it is presumptively rational for a legislature to draw lines in ways that match traditions or common contemporary practices. As the amount of required linedrawing increases, and it becomes harder to justify one specific line over another, it becomes rational for a legislature to simply mirror the status quo rather than craft a new approach ... My claim — albeit only a very tentative claim, as this isn't my area and I haven't looked closely at the cases — is that the fact that some line needs to be drawn, and the legislature unimaginatively drew it in some relatively traditional way, itself helps provide a rational basis for the legislature's approach.