Fear mongering, are you kidding? I don't give a rats ass who marries who (refer back to a year or so ago). I don't care if someone marries their dog (Lefty

), why do you care?
Try to look beyond this one decision. Ever heard of incrementalism?
The point is, once you make an argument that legal marriage is not just between one man and one woman, then that same argument can be used to justify the marriage of anything. Think about it, if the government cannot dictate who you can love and make a lasting connection with, then how can they limit it? So, what makes love between a man and woman, or a man and man, or a woman and woman any different than between a man and a sheep?
If you can make an argument that a man can't marry a dog or a woman can't marry her brother, then maybe you can begin to understand people who argue against same sex marriage. But I seriously doubt you can understand anything but your own point of view..........which will make you a great (typical) lawyer.