By invoking an Equal Protection argument, the majority has signaled that a State which denies gay "marriage" is denying a "right" to its citizens that are enjoyed by other citizens of the state. All homosexuals now need to do is bring suit in a state with a DOMA-like Constitutional Amendment or statue, and it will fall once challenged in Federal Court. The State's Rights arguments advanced by Kennedy were simply a means by which the liberals -- none of whom give one crap about State's Rights -- used to bring his vote into their camp.
Scalia saw this clearly, which is the reason for his savage deprecation of the majority's opinion.
“DOMA essentially no longer exists, so there is nothing to shield. What Krauthammer is correctly saying is because Kennedy also invoked equal protection, that all that has to happen is someone gets federal benefits in a homosexual marriage state, moves to one that does not have it, then sues under equal protection, forcing all states to recognize homosexual marriage.”
They did leave to door wide open for an equal protection case.
The path to an equal protection claim would be through the 9th Circuit.
The best strategy to prevent such a case moving from the 9th Circuit to the Supreme Court would be to have gay marriage in all the states within the 9th Circuit.
With such a fire wall petitioners would have to go to another court instead of the 9th Circuit which will make it much more difficult for them to win and take much longer to enact on a national basis.
“all that has to happen is someone gets federal benefits”
Federal benefits are the attack vector. If there were no federal benefits this attack could not occur.
Federal benefits exist so as to be comparable to private enterprise. Americans have become accustomed to employer paid “benefits”, aka medical insurance. It had been the case that routine medical care was generally affordable and insurance reserved for catastrophe, if at all.
Every step we take from rugged individualism towards communitarianism leads not just to diminished freedom, but also to attacks on foundations of society.