Dennis Prager has a good post called:
Why a Good Person Can Vote against Same-Sex Marriage
Changing the definition of marriage is bad for society.
I love this paragraph:
The history of left-wing policies has largely consisted of doing what feels good and compassionate without asking what the long-term consequences will be; what Professor Thomas Sowell calls “Stage One Thinking.” That explains, for example, the entitlement state. It sounds noble and seems noble. But the long-term consequences are terrible: economic ruin, a demoralized population, increasing selfishness as people look to the state to take care of their fellow citizens, and more.