I believe you should derive morals from reason, and not by voting or cultural "feelings".
The foundation of my ethical system is that I believe that it is in general wrong to initiate the use of force against another person. Peter Singer's works explore the implications of this, and the reasoning behind it.
So, in general, a society voting to not provide equal consideration to some of its members, based purely on their sexual preference, skin color, religion, or which side of their eggs they crack open would not meet my standard of "moral". Or acceptable.