The majority in Lawrence expressly refused to decide the case on the basis of equal protection.
But their reasoning included an 'equal protection' type argument.
Do you think that there is any remaining room for any state to create or apply any laws in a way that impacts homosexuals differently than normal people? I don't.
The only possible out is that O'Conner may recoil from the necessary application of the reasoning of Lawrence when she is faced with real cases. So she will split yet another hair that noone other than her can even see.
Lawrence is the final step by the Court in eliminating any textual significance to the Constitution. It has been replaced, sub silentio, by a federal common law comprised of what five justices think is a good idea at the time. This is really much more than the Court cutting itself completely loose from any notion that they are actually interpreting a document. It is the arrogation of the power to decide any dispute, any time in a manner destructive of a Federal Republic.
It was an appalling decision.