Such comparisons are standard fair from conservative people, conservative politicians, etc (and for the record, Scalia is considered a conservative jurist). These people do so to scare people who do not know any better into being against marriage equality specifically and homosexuality/LGBT equality in general. A Supreme Court justice should know better. They should look at actual facts instead of dogma, they should look at law and not personal prejudices. The difference between murder and bestiality on the one hand and marriage equality on the other should be self-evident for anyone with functioning neurons. Scalia is clearly lacking in this department. Obviously murder is the act of taking the life of another in cold blood, and murder and bestiality are both acts that involve something happening to another with no legal consent. What do either have to do with a consensual relationship between two people of the same gender? Absolutely nothing. I did not have to go to law school or take a bar exam to understand this. All it takes is simple logic and a mere moment of thought. A Supreme Court justice should be more than capable of making these easy distinctions.
If Justice Scalia can not get that, then he needs to resign from the Court immediately. He is obviously not intelligent enough to serve on the highest court in the land.
Update: I wrote this just before news of the school shooting in Connecticut broke. Obviously what happened there was an absolute tragedy and the only reason I'm not really addressing it is for personal reasons. My thoughts and prayers go out to those affected.
This week saw the Supreme Court decide to take up the issue on two fronts: California's Proposition 8 (Prop 8) and the constitutionality of the so-called Defense of Marriage Act (DoMA). One of the most outspoken critics of marriage equality is the co-founder of the National Organization For Marriage (Discrimination), Maggie Gallagher. She issued an interesting statement on SCOTUS taking up the aforementioned pieces of legislation. While she said that the court will quite likely uphold Prop 8, she also said the court will likely throw down DoMA.
Of course there are many people on the other side of this issue that are still saying this fight is not over and they will win in the end. Ever so slowly however, there are fewer people of that mindset. Increasingly they are reading the signs: voters supporting equality on the ballot, younger people supporting equality more than older voters, more emboldened states taking up the cause of equality like Illinois (which plans a vote in January). Hearing social conservatives conceding these facts (even though they continue to fight against them) is certainly heartening. Yet we should not take all of this for granted. The battles will go on even if SCOTUS throws down both Prop 8 and DoMA, and we can not stop fighting.