Response to Michael S.'s Response

This is when I think a comments function might make sense for MOJ.  I don't want to leave Michael's question hanging out there, but I'm not sure this deserves an entire post.  That said, in response to Michael's response:  you are not missing anything.  Your response answers my question.  I take it, then, that your position is that, in light of the history particularly grave injustices in a given society, laws banning those injustices are necessary (presumably for expressive purposes) even when the practice itself has largely disappeared.  (I think slavery is a reasonable analogy here, although I think the two cases are substantively quite different.)  I think that it is a position that has some merit and does not obliterate the distinction between morality and law.