If the 14th Amendment guarantees the right to same sex marriage, then same sex marriage has to be legalized. That was the precedent set here--following the constitution and the rights it guarantees to all citizens. Many of the arguments that Scalia made could easily have been made against allowing interracial marriage. Likewise, they could have easily been made against abolition, or integration. What the 14th Amendment does is fight the "tyranny of the majority"--it protects the rights of marginalized groups from majority rulings.

If the majority always had its way, slavery and segregation would still be legal. Sometimes the majority is wrong. Just because a lot of people believe something does not necessarily make it right. Several hundred years ago, the majority of the people believed that the sun revolved around the earth. Seventy years ago, the majority of Americans believed that the races should be segregated. Sometimes, the majority takes away the rights of the few--and in those instances, we should be grateful that a document like the Constitution gives the Supreme Court the (seldom-used) ability to overrule the majority.