Amicus Curiae Brief of Dr. Paul McHugh in Support of Hollingsworth, in the U.S. Supreme Court Same-Sex Marriage Cases of 2013
This brief successfully argued that sexual orientation should not be recognized as a new suspect class. In contrast with other suspect classes, it is neither discrete (clearly definable) nor immutable. There is no scientific consensus on how to define sexual orientation, and the various definitions proposed by experts produce substantially different classes. Nor is there any convincing evidence that sexual orientation is biologically determined; rather, research tends to show that at least for some persons sexual orientation is mutable (or at least malleable).