When debating with someone that is for gay marriage I often say, "I want to marry my dog and claim our puppies as dependants." While they are going on about why I can't do that, I have to give them the old - "Who are you to judge!?" response.
I really don't care who or what people want to marry but there are reasons we have laws against beastiality/ animal cruelty.
Yes there are reasons we have laws period and the problem with the system is it enforces them with whomever they please and disregard those they please. Without impartiality and honor the legal systems cannot and will not stand. The Justice Department has made the stand so it is up to us to fix it or allow the strongest to survive.