Gay marriage is a perversion of God's law. It creates nothing and destroys nothing.
Calling a donkey a horse doesn't hurt the horses. It just hurts those too stupid to see the difference.
It also hurts the children of those who are smart enough. Maybe your children's marriage won't be hurt, but their children's will.
Shalom.
Remember that these people will be allowed to adopt children. The welfare of these children hangs in the balance.
These laws also serve to destroy the notion of the natural law with respect to marriage, and reduce marriage to a purely utilitarian, contractual arrangement. This will impact men and women in natural and sacramental marriages, and their children.
We are our brother's keeper, so we must work to prevent the passage of these evil laws.