Loving v. Virginia was about anti-miscegenation laws. Such laws were ruled to be a violation of the Equal Protection Clause of the 14th Amendment, because such laws were about a status. You can't realistically change your race (Michael Jackson was never realistic about anything), but you can choose with whom you want to have sex (subject to the other person's consent).
If gay marriage is permitted nationwide, marriage will become a joke. The polygamists will call for legalization of plural marriages and they will easily win. At that point whole groups of people will marry one another for the government benefits (imagine a marriage consisting of 24 men and women). After that, State governments will save money by ceasing to recognize any marriage.
That's the point of all of this. They want to destroy marriage by making it a cultural joke and removing its special place in the law.
That is the nuclear option (actually favored by some libertarians); don’t have any state recognition of marriage at all.
While I completely reject the idea that the state must recognize gay unions if it recognizes traditional marriage (you can only arrive at that with a ‘living Constitution’ view), I would probably prefer no recognition of any kind for any unions to having to bow down before yet another outrage from the Sup Court. Though if that happened, the Supremes would probably come back and say the state must recognize marriages.