Homosexual incest is the probable door through which a general right to incest is discovered. What is the compelling state interest in prohibiting sodomy between two adult brothers, or sisters?
As of Thursday, there is none. From there, we're an equal protection argument away from a general right to consensual adult incest.
The genetic objection to a legalization of incest is already on shaky ground, since most incest doesn't result in birth defects. Those who want to discover a right to sodomy, but hold the ground on incest because of the possibililty of birth defects, will have to cartwheel like a gymnast to explain why there isn't a state interest in regulating all extramarital heterosexual sex, since STDs can also induce birth defects.
There's obviously nothing to keep the SC from effectively legalizing incest, bestality, or basically whatever sexual perversion they wish at this point..
If you toss out the Tenth, the the power of the fed is completely unchecked in this area.
Regarding Limon, antiguv pointed out on another thread (actually a thread that I think was quite productive) that Limon merely wants the lower court to review its rational basis decision for having a different sentence for homosexual rape and heterosexual rape bearing in mind that its citation of Bowers as a part of its argument is now no longer appropriate. There may be less here than meets the eye, although I suppose SCOTUS could have found the citation harmless error and be done with it. We shall see, but I would be amazed that if the lower court still finds a rational basis for the differential sentencing, that SCOTUS will grant cert again on the matter. Of course, I was surprised by the grounding of the decision in Lawrence (not the result), so surprises do happen.