No matter how you feel about gay marriage, we should be able to agree that the citizens and their elected representatives must not be excluded from a decision as fundamental to society as the definition of marriage. There are lessons from my state's experience that might help other states preserve the rightful participation of their legislatures and citizens, and avoid the confusion now facing Massachusetts. In a decision handed down in November, a divided Supreme Judicial Court of Massachusetts detected a previously unrecognized right in our 200-year-old state constitution that permits same-sex couples to wed. I believe that 4-3 decision...