Within a few days, a federal district judge in my home-state of Virginia will likely rule on the constitutionality of the commonwealth’s Marshall-Newman Amendment, which only permits marriage between one man and one woman. Frankly, as a conservative Republican and as a Christian, I hope that the amendment is struck down. Republicans value marriage so highly because it encourages people to live according to conservative values. For instance, by enabling two people to share resources, marriage makes couples more financially secure, thereby reducing their dependence on government. In addition, marriage binds people into permanent, monogamous relationships, enabling couples to more...